There are several decentralized exchanges that are good and reliable such as uniswap, justswap,
binance dex, etherflyer. I still believe in the quality of decentralized exchanges, maybe some not trustworthy it because of fake exchanges and no volume
Yeah volume also one of the factors. iam not really sure but not all Dexes are not trustworthy but tbh iam still more convincied to trade on cex because for me it's more realiable and more safer