Blockchain also has some useful applications. Most (but not all) of them are also possible with technology and such that existed when bitcoin was first created, at far lower cost for a minor tradeoff in accuracy. On top of that, almost none of them are related to speculative markets.

It's a way to do distributed transaction logs in a non-refutable and independantly verifiable way. That's useful and important, but it was a solution in search of a problem. Even for the highest security, most at risk transactions, the existing international fincancial systems are "good enough" to ensure reliability of transaction logs.

In the end, blockchain and now AI are just falling victim to con men trying to milk as much money as they can from things before people build a working understanding of them. They'll just keep moving onto the next big thing as it comes.