I sympathise with this, and part of it's down to the glacial pace of regulators (which as a consumer I find frustrating).

At the same time, for a number of years there was a lot of perceived legitimacy to a lot of crypto exchanges. Sure, there were obvious scams, but some of the bigger players were putting on a convincing "this is actually useful and beneficial to consumers" trenchcoat. I also see the perspective from the SEC of "let's not be too hasty", and to wait to see how it shook out.

In hindsight, sure. Obviously scams and they should have been shut down years ago.