I do not know.

Your points you have brought up are definitely part of the story, but it doesn't explain everything. There is more... something else... something greater.

My feelings are that many of the big names in exchanges are just fronts for the people behind the banks.

There are too many trading shenanigans that go on.
And we all know bitcoins entire market cap (not what is traded) isn't enough to handle but a small percentage of the illegal drug market. That takes the biggest banks to move that amount of money.

So... the KYC was about something else. The Binance leaving The US is about something else.

i don' trust any of em further than i can throw em.