My friends lost money on such exchanges. They had several thousand and traded for several years. After transferring 20-40 thousand dollars to the exchange, their funds were blocked.
Anyone who manages to create an exchange that combines the benefits of DEXes and CEXes will make a killing. It could be a low-latency DEX or maybe a no-KYC CEX with some kind of really smart contract that guarantees the user that he would be able to withdraw his funds thus guaranteeing that the CEX won't be able to block the funds and require a KYC. Or maybe some other kind of system that provides the benefits of both kinds of exchanges.
But joking aside, most people, including those so called "hackers" don't have a deep understanding of computer security and security in general. So they are rather easy to catch and the main reason some of them are able to get away with their petty crimes is that the governments are busy chasing the big fish and the small ones are not paid attention to. Anything related to the banks' electronic money and the governments' CBDCs is trivially traceable by the government. If we add the fact that transactions of most popular cryptocurrencies are publicly visible and we can be sure that for most people crypto does not add any privacy.
A friend of mine has over a million dollars on the exchanges, and his lawyer contacts the VIP manager of the exchange every quarter and provides the exchange with tax returns and all the necessary documents, and even despite this, the trader’s account is blocked several days in a year.