I think there's a bit of misunderstanding between what defines a DEX and a CEX. From what you've described, it seems you're leaning more toward building a DEX rather than a centralized exchange. And you focus more on crypto-to-crypto transactions instead of crypto-to-fiat.
There are still some centralized exchanges that are privacy focused. Example is exch exchange that will shut down on May 1 because of the Bybit funds Lazarus group sent to the exchange address for exchange into another coins. The exchange is centralized but it has no KYC and you can even use Tor to exchange coins
inon the exchange.