If you asked someone 10 years ago what the hottest technology of the 2020s would be, they would probably have said “blockchain”. It was all the rage. Forget bitcoin, they said, the real value is in the underlying technology that secures it, the blockchain.

A blockchain is a distributed public ledger, cryptographically secured by a network of computers, all running the same algorithm, and all voting on the validity of new records and changes to the algorithmic rules.

This article is part of a series about amazing technologies that promised to change the world, but did no such thing. Read: The train that never came – how maglev technology was derailed

It is the technology behind digital currency systems, the most prominent of which is bitcoin. Its strengths? No bad actor or group of scofflaws can modify the digital record without the consent of the majority; the ledger is open to public inspection; and records, once cryptographically signed by consensus, cannot be modified or deleted.

What they said

Here’s Big Think, circa 2016: “This article is not about bitcoin. What it is about is the verification system that enables bitcoin. It’s called the ‘blockchain’. It embodies … a concept that has a profound potential to change our lives. While bitcoin already uses a blockchain, it’s likely many more things will in the future. It’s such a cool concept.”

Potential applications, the article said, include financial records, personal and business authentication, property records, smart contracts and automatic dispute settlement, cloud data storage, and secure messaging.

“It’s not a perfectly worked-out system yet, but the blockchain is an incredibly promising concept that may well stand behind much of what we trust in years to come,” it said.

Another article from 2016, in Aeon magazine, agreed: “Blockchain technology will revolutionise far more than money: it will change your life.”

It also de-emphases bitcoin, the killer application for blockchains: “Bitcoin is currently experiencing some governance and scalability issues. Even so, the tech works, and coders are now developing ways to use blockchain tech for purposes beyond an alternative money system. From 2017, you will start to see some of the early applications creeping into your electronic lives.”

Those applications include all the aforementioned, plus online reputation, as well as elections.

“The revolution will not be televised, it will be cryptographically time-stamped on the blockchain,” the article concludes. “And the blockchain, originally devised to solve the conundrum of digital cash, could prove to be something much more significant: a digital Domesday Book for the 21st century, and so much more.”

Some idiot

And here’s some starry-eyed idiot on Daily Maverick, writing in 2014: “Beneath all the hype of bitcoin, a true revolution is happening. It isn’t about quick profits and market speculation, but about the technology that makes it all possible: the blockchain. It has the potential to transform society and free people from the constraints imposed on them by government and big business.”

He concludes: “The blockchain as a concept is more than just a move to encrypted, decentralised transactions and applications, some of which may prove useful and sustainable. It will help to fix the internet. It will erode the power of governments and big business, in a way that makes the world more free, less expensive and more productive.

Read: Bitcoin hits fresh record amid investor optimism

“It will return the internet to its lost ideal: a place where free exchange of speech, services and goods can flourish. It will return government to its proper sphere in a free society; one in which its affairs are public, and those of citizens are private. To appropriate a quip about beer: ‘The blockchain will change the world. I don’t know how, but it will.’”

What was he thinking? Doesn’t he feel like a fool today? (Spoiler: the idiot was this very author, 11 years younger.)

Hottest technology

Turns out the hottest technology of the 2020s is generative artificial intelligence, by a long way. Blockchain probably doesn’t even make it into a top 10 list of the decade’s most influential technologies, behind less sexy entries such as 5G, the internet of things and smart devices, video conferencing, media streaming, computer vision, autonomous robots and vehicles, edge computing, biometrics, 3D printing, big data analysis, and data visualisation.

Blockchain technology does have strengths, and it certainly does have applications, including securing cryptocurrency transactions.

However, the features that make it excellent for that purpose do not necessarily make it well-suited to other purposes.

Applications

Financial records and transactions? Great, blockchain is very secure, immutable and resistant to fraud, but who really wants all financial transactions to be transparent and publicly accessible? Who wants to establish a broad peer-to-peer network to authenticate financial records? What does a blockchain really add that a bank’s centralised database systems cannot do just as well?

Asset registers? Sure, blockchain can do that, but so can a traditional database system. The most hyped use of blockchain other than cryptocurrencies was non-fungible tokens (NFTs). And while NFTs certainly do have potential applications, their most high-profile use was to monetise digital images of monkeys. Most of the NFTs that sold for high prices are now worth zero.

Cloud storage? Blockchain can’t do anything valuable that a corporate data centre, a peer-to-peer file sharing network, or the interplanetary file system can’t already do.

Identity verification and authentication? Who wants their identity lying around on a public blockchain for every crook and their mate to exploit?

Messaging? Again, a public blockchain is probably not the best way to create true security, or preserve online anonymity.

Smart contracts? They sound very cool, but they are inflexible and complex to set up. Now you need not only a contract lawyer, but also someone who is intimately familiar with decentralised financial technology, just to conclude a contract. And so does the counter-party, who is unlikely to even know what you’re talking about.

Advantages can be disadvantages

And even if you had all these resources, which particular blockchain should you choose?

There are over 100 level one blockchains out there, and hundreds more subsidiary chains. They’re not interoperable. So if you’re working on blockchain A, and your counterparty uses blockchain B, one or both of you are going to have to switch in order to do business together.

One claimed advantage of blockchains is their transparency. Anyone on the network can inspect and verify blocks. But that is also a disadvantage. A lot of records for which we now use databases are meant to be confidential. There are workarounds to solve this privacy problem, but that only makes the blockchain opaque, which was the problem they were meant to solve in the first place.

Read: Burning millions on the blockchain

The distributed nature of blockchains is also cited as an advantage. But if all the nodes on a network have to maintain a copy of the entire ledger, then blockchains are highly inefficient means of storing data. Add to this the idea of “proof of work” to secure blocks, and you’re burning far more energy just to maintain a secure blockchain than you would use to maintain a database in a data centre.

Market forecasts

Market analysts continue to predict massive growth in blockchain technology.

According to one estimate, between 2017 and 2024, the blockchain market grew from just under US$1-billion to $32.7-billion, which represents an average annual growth rate of about 65%, albeit off low base.

Most market forecasts seem to assume that this spectacular growth rate can and will be sustained for the foreseeable future.

For example, Precedence Research says: “The global blockchain technology market size was estimated at $26.9-billion in 2024 and is predicted to increase from $41.1-billion in 2025 to approximately $1.88-trillion by 2034, expanding at a compound annual growth rate of 52.9% from 2025 to 2034.”

MarketsAndMarkets declares: “The global blockchain market size is projected to grow from $32.99-billion in 2025 to $393.45-billion by 2030 at a compound annual growth rate of 64.2% during the forecast period.”

An even more optimistic Grand View Research claims: “The global blockchain technology market size was estimated at $31.28-billion in 2024 and is projected to reach $1.43-trillion by 2030, growing at a compound annual growth rate of 90.1% from 2025 to 2030.”

The difference between 50% and 90% annual growth is massive, which suggests they’re just guessing, and the assumption that historical growth rates will simply continue for many years is pretty wild, so I’d take these forecasts with a pinch of salt.

The real revolution

There are certainly untapped markets for blockchain technology. Supply chain management is a big one. Cryptocurrencies are, of course, going nowhere, and once central banks get in on the game, in an attempt to save fiat currency from the threat of truly decentralised, peer-to-peer money, they’ll use blockchains, too. The decentralised finance industry is also likely to continue growing, albeit off a low base.

So, I’m not suggesting there are no applications for blockchain technology, or that they won’t find new markets and greater adoption in future. But I’m no longer convinced they’ll change the world, fix the internet, or free humanity from corrupt and authoritarian governments.

On the day I wrote that 2014 article for Daily Maverick, bitcoin closed at $375. As I write this, it is trading at $121 250.30. That’s a 320-fold increase, at a compound annual growth rate of nearly 70%, sustained for 11 years.

Read: Crypto industry shoots for mainstream adoption

I keep running into “bitcoin accepted” and “bitcoin preferred” stickers, even in small towns in South Africa’s hinterland. As it turned out, the real revolution was bitcoin, and not just the technology that enabled it.

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