Decentralised exchanges will always top these centralized exchnage due to high level of security Dex has over cex. If these exchanges upgraded their system to enable users have custody of their funds auxh hacks won't take effect on the exchanges.
Dex are good but the problem with them are the lacks of improvement. How many decentralized exchange were succesful on creating liquidity and volume you can nams only few. But centralized exchange has advantage over them since a lot of users like high volume on trading. But the sad fact remains that these cex has been not safe from breach. Even Binance has been hacked with lots of fund considering its one of the top most exchange.