Shouldn't it at least be possible to identify them, by following the crypto addresses until someone cashes out? I get that you might not be able to do anything

Shouldn't it at least be possible to identify them, by following the crypto addresses until someone cashes out? I get that you might not be able to do anything about it if they are sheltered from prosecution where they cash out. But I don't get why we can't at least, to some reasonable degree of accuracy, say Address A took the ransom and eventually it ended up with Address Z cashing out through Exchange B. Then if either Exchange B or Address Z has anything at all to do with the US-dominated international financial system, you've got serious leverage. If I'm Coinbase, am I not worried about unwittingly laundering money for terrorists? Don't I have a staff trying to prevent that?