> Why do you think you can dismiss the obvious claim that cryptocurrencies are a form of decentralized finance with a "no, it isn't"?
They are or can be a form of decentralised finance. That doesn't mean a system that is totally parallel to the legal system. And, again, different people intend different things with it. It's definitely not all "code is law" people.
What "intended uses" are there for it other than being an unregulated options market with constant scams and a "code is law" tool?
I would imagine any other legitimate use would be served better by traditional database/finance systems.