Even legitimate gambling websites do this, I was able to cash out £150 fine but a few weeks later when I tried to cash out at £700 I had to supply id. I was still able to deposit more money from the same card though, supplied my id, cashed it all out, told them to delete all of my details and account and never looked back

So the trick is to find a bunch of scammers to try this on

That's not a trick, that's a legal requirement. They have to do KYC on a few grand and AML once it gets bigger. I had to go through this with Wise when I received a life insurance payout from another continent and I had to phone customer support to get it cleared.