You do know that most faang employees work on methods to maximize ad revenue right, because last I checked google or Facebook weren't in the business of trying to cure cancer? What about Lockheed-martin or other companies making missiles that kill civilians for their oil?
Blockchain is just a technology, one shouldn't have such strong feelings against it just because one is a contrarian and lots of idiots are shouting that it'll end world hunger or building scams using it.
You speak of machine learning and cryptography, both are tools, some use ML techniques to discover tumors in medical images before humans can spot them, and others use it to analyze your data to know which product should be advertised to you to make you spend more money on useless things.
I am definitely a cryptocurrency contrarian, so I was going to stay out of this thread - it wouldn't help OP to have people questioning his fairly straight-forward request.
But I don't think there is such a thing as "just a technology". Technology comes out of people's desires, and you can't disentangle it from the context it's created in. You can argue that blockchain is just an append-only database, but that ignores all sorts of externalities its adoption is causing.
This would be true if cultures didn't change, but they do. Switch your argument to something else, say splashing water on fires using tools. By your logic the technology can't ever be disentangled with the purpose of extortion, a bad purpose. Yet time passed and now firefighting isn't an extortion in which your house burns down unless you pay the firefighters. In that case, splashing water on fires really is just splashing water on fires. It also isn't like the business model was without perverse incentive - start a fire and you potentially get paid for putting it out.
This isn't me saying you're wrong that people are making a mistake in ignoring externalities, but more that the reason why it is a mistake isn't that they correctly articulated one component in the problem they were thinking about - its because they ignored the other stuff which interacts with it.
Blockchain is just a technology, one shouldn't have such strong feelings against it just because one is a contrarian and lots of idiots are shouting that it'll end world hunger or building scams using it.
You speak of machine learning and cryptography, both are tools, some use ML techniques to discover tumors in medical images before humans can spot them, and others use it to analyze your data to know which product should be advertised to you to make you spend more money on useless things.