If an oligarch extracts wealth from Russia and parks it in London... that seems like a win for London?

It is a bit anarcho-tyrannical in nature though. That is, the AML/FCA stuff then has the outcome of only effectively constraining the UK's own law-abiding citizens. Which is... something of a disadvantage?

Especially when half of what the FCA puts out in terms of regulations is pure time-wasting theater.