The problem is that people prefer convenience over safety and security and sadly, the decentralized exchanges are not as newbie-friendly and easy to use as the centralized ones and that's exactly what pushes people away.
Decentralized can't beat the centralized exchange, they are just an option for those people who can't and don't want to use the centralized exchange for whatever reasons. But let's admit, having them in the crypto space is always a big help and it serves traders that are not serve by centralized exchanges.
But let's face it most people like decentralized exchange but couldn't use it on every crypto.
We are stuck in centralized because most of the famous and known exchange are CEX.
But if there would be a DEX for all crypto why wouldn't people choose it?
After all crypto is design for being decentralized for anonymity and for financial freedom to be out from those third parties .