IMHO, Tornado Cash was sanctioned not because of its tumbling function per-se, but because hacking groups were using it massively to launder eth or eth tokens. And again that was because most hacks were/are made in ethereum and eth-like shitty vulnerable protocols or bridges. Not to mention all those lending website disasters.

On a side note, since most protocol-level developments in Bitcoin are decentralized and carefully made/reviewed, I don't see that many hacks happening on btc.