Money, liquidity, and fungibility is a public good, it has been (and still is) a waste of public and private resources to attempt to alter that reality. Although this isn't a popular or public opinion by the public or banks or politicians, it is also the reality for banks and their host governments, and all lip service otherwise is either a lie for data collection or simply fails spectacularly at actually preventing…
I believe KYC is a very good idea fundamentally, and I wish more banks took it seriously with their top customers as well (or more) as with the rest. It’s not in banks’ interests, of course. And I disagree that terrorism is cheap. Preparation for 9/11 allegedly cost up to $500K. Bojinka plot used fair amount of financing as well. Maybe those couldn’t be caught via financial controls and KYC, or maybe they could.
With billions slipping through from any random branch manager at any bank anywhere, how many 9/11s is that? Any time, for any reason, funding secured.