Probably everybody heard about the Tornado Cash sanction and now the resulting arrest of its developer:
Common regulatory requirements by FinCen, FATF and other institutions have always been based on the main requirement for regulation, the funds have to be somehow in custody. We can maybe suspect Microsoft shutting down the Github repos and accounts without strict requirement, but arresting the suspected developer of a smart contract which is not centrally controlled (at least by him, don't want to open a discussion wether the base protocol is decentralised or not) by anyone after it has been published makes a huge difference. The only issue one might see him as a service / product would be fees he was getting from everyone running the contract and entering the pool had top pay.
Now how does this reflect to decentralised exchanges like Bisq or Haveno and atomic swaps with other chains? DEX obviously also run on fees and allow users to swap their coins between each other, quite similar to Tornado Cash. Atomic swaps are feeless rn, however those might also be implemented by some meeting point providers. Both at no point touch the coins of their users, only provide the code / platform.