Crypto assets may not be FDIC insured, but Coinbase can't just steal and run away with your assets without facing legal ramifications in the U.S. And that would also mean founders/shareholders face consequences (look at Theranos). Of course they can still go bankrupt. But then, again, the U.S. courts would decide what happens to their assets and yours. In either case it's up to the U.S. legal system, i.e. government.

That's very different from managing your own keys. Nobody can take anything from you. But you also have zero legal protection against an attacker stealing your keys. In other words, you are in full control, for better or worse.