Non sequitur. Banks generally have to have KYC to do business, though there are famous exceptions in history. There is no jurisdiction I know of in which as a customer not providing KYC is itself a crime.
The law here notes even some CFRs are criminally binding, the CFRs explicitly require certain identification.
What happens if the banks don't close it?
Example? Every one I can think of involved the bank not doing KYC, criminals taking advantage of it, and evidence at least some people at the bank knew what was happening. (Usually because authorities told the bank they were doing business with criminals and the bank responded by shuffling things around so they could continue doing that business.)
The difference is if the bank does KYC and the criminal uses a dark identity, the bank will likely get away with it. If the bank just gives each person a random number as their only identifier like the old swiss accounts, then they'll be warned sanctioned entities are using it and ultimately prosecuted when they fail to KYC (i.e. similar but but identical to CZ).
What is a dark entity? Have you worked in finance? Because if you collect KYC and accepted forged or faulty documents, the moment you figure out what's going on is the moment you call your personal lawyer.
Sure. If you're at a financial institution and accept that documentation, you're personally in for a world of hurt. Doesn't mean it doesn't happen, either due to someone being negligent, overworked or happy to look the other way. But if it's caught, it's not great for the individual. (The bank will survive after paying a fine unless it's systemic.)
Sure. But if the addict you mentioned's account goes from overdrafting every few weeks to holding millions of dollars, that should set off internal alarms.