I used to think hackers only used mixers to hide stolen cash but they've got other tricks like P2P trades or swapping across blockchains. Mixers are part of it, sure, but pointing at them alone misses the bigger mess. I'd say better tracking tools and beefing up exchange security could hit the problem harder.
when it comes to interchain bridge the hacker don't really erase their trace by simply bridging though, the bridge can easily disclose where the money going on the other side of the blockchain since they also retain their own ledger for this and in the recent bybit hacking, most of bridges has been cooperating so far. meanwhile mixers are privacy tools and well, not easily disclosing where the money went.