Money laundering has the benefit of Federal law working to help the State laws. I think in an environment where there are 50 different legal regimes it's inevitable people will develop workarounds. You see legal arbitrage in every instance where legal differences exist between states. From corporate law to family law. I don't know why this would be any different.

If you want to stop the hackers, make it a Federal crime to pay anyone. In that environment, there would be no circumventing the restriction at all.

Not really: money laundering typically is an on-going activity, while ransomware/hostages is (hopefully) incidental.

That means that money laundering laws are up against a dedicated adversary with resources, while laws preventing ransoms... not so much.

Of course, with cyber insurance, incentives for the insurer may lean towards dedicated circumvention.