To me, I think Centralized exchanges are more user-friendly than DEXes due to which people don't like to visit their websites while they can do all the trading on a CEX app like Binance, Kucoin, Hotbit, etc. and that's the only reason why DEXes don't have much volume. Most of the DEXes I've seen are mostly based on Eth smart contracts, but I believe that Eth itself is Centralized so how can those DEXes be called as decentralized ones?
but if you keep all your assets for too long at the exchange place it will pose a very high threat to you because the place of exchange can inadvertently collapse and there will be many assets that cannot be liquidated and held at the exchange place, there have been many cases it happens like that, so I think you should be able to be careful when storing assets in an exchange place.
No need to talk about the crash, we just need to talk about the case where these centralized exchanges were attacked by hackers then stealing assets from their wallets, this scenario is enough for us to see the risk of storing and turning these exchanges into banks. The crypto world doesn't need an exchange to become a bank, they just need these exchanges to work properly and be accountable, the assets that investors own will be stored in their own wallets at crypto wallet websites trustworthy or hardware wallet