At one point, mixers were celebrated as the harbingers of liberty and privacy on the forum.
At that point, we didn't have tested, decentralized privacy tools in our disposal. Using a mixer was the easiest and sort of most reputable manner to receive fungible coins. It no longer is. Decentralized tools like Bisq, Monero, or self-custodial coinjoin software like whirlpool, are developed and used every day.
The origins need to be obfuscated so if ill-gotten/ hacked BTC is to be cashed out, you eventually need to go for a CEX which will probably need KYC.
If you really need to go through a CEX, you can still retain your privacy without buying taint. Just convert them to XMR and sell the XMR.