My point is that something is not useless if it has the potential for future use. I would, for example, not call the example in the article (in any stage of its development) useless because it has the potential. Same for any possible paradigm-changing work. If it is proven (in the strictes sense) to not work, then it could be deemed useless.
Now if something is profitable is a whole different thing.
The thing is you don't know that it's got actual future usefulness. You might think or hypothesize that it does, but for various reasons it may turn out to be a dead-end.
Almost every endeavour has non-zero potential future utility - even as a counterexample or lesson to learn from. I think that definition of "useful" is probably too broad to make an argument against, and so not a useful definition.
And you have spotted the early stage opposrtunity most VCs fail to fund: paradigm shifting work often looks like infrastructure, very broad and general-purpose. It can eventually lead to trillions of dollars in wealth creation (the Web, Linux, smart contracts, etc) but the first movers may capture 5% of the ecosystem’s value. For a VC, that’s a bigger bet that can change the world a lot more than, say, the next short term memecoin sold to the greater fool for 50x or hype app dumped on the market for 100x.
Paradigm work has always run on patrons. A new paradigm is useless at the beginning, by definition, so markets have nothing to price. The first personal computers were toys. So was the early internet. The people who fund this stage are buying a position in the future before anyone can price it.
Well, some of us are drawn to this world-changing work (Vint Cerf who’s retiring this week, Linus Torvalds, Tim Berners-Lee, Vitalik Buterin, Jimmy Wales, Igor Sysoev etc etc) and it runs most of the Internet. But, will it get funded?
Now if something is profitable is a whole different thing.