There are zero trust protocols within some crypto ecosystems and some of the world's top crypto PhDs work on these projects. There are just so a lot of amateur devs and uneducated users trying to make a buck, of which get exploited by a much more sophisticated party who also wants to make a buck, sounds like pretty much any other capital market just much more blatant.
Or, I can buy USDT and move it to my cold wallet and call it a day.
Yeah, but if you get wronged on normal capital markets you can complain at the authorities and get your money back. Your bank goes bust? FDIC covers up to 250k per account. Your credit card company doesn't side with you in a dispute or your bank's customer "service" department acts up? Call the CFPB, and you'll get a call from somewhere very high up the bank's chain who actually has the power to make things happen to make sure you withdraw your complaint. A public traded company does bullshit to mislead investors? The SEC will tear them a new hole. And so on.
In the crypto world, you're left to deal with all of that on your own. Maybe the police will file a fraud complaint that won't lead anywhere.