While this is true, there are still those who do not yet require KYC with a daily withdrawal limit. Taking this into account, it is possible to send BTC anonymously to CEX if we make them anonymous in some way before that, and then sell/exchange them there for another coin. However, the whole thing would not make sense if, after all, we sold that BTC and withdrew the fiat to our bank account.
Not all require KYC, you are right about that, but they reserve the right to request it if you get on their radar by doing anything suspicious. What is considered suspicious depends from exchange to exchange. The sole fact that the money originates from gambling activities or mixing services can be enough for them to say: hey, who are you, and where did you get those coins from?
When we are talking about centralized exchanges, I see FTX being mentioned more and more in the last months. It's got a decent exchange rating on CMC (not that it matters though) and big daily trading volume.