If an American citizen trades crypto on a foreign exchange, AFAIK any gains are still taxable. If an American citizen withdraws fiat to a foreign bank, those banks still report to the IRS. I understand how Binance evading reporting is an issue for the US GOV, but I don't really see how it matters as an exit strategy for US citizens. If I want to open a bank account in another country and just wire money there I can do that without jumping through the hoops of opening a crypto account.