Decentralized exchanges are very very good especially for countries that has banned exchanges. As obviously, you wouldn't need KYC on decentralized exchanges. Like what the previous replies said, the downside is definitely the UI/UX. They're so bad that you'd actually have to do research on how to use the exchange's functions. That's why people use centralized exchanges like Binance instead. Simply because exchanges like Binance are miles easier to use than DEXs we have currently. Binance announced that they're currently building their own DEX though, so let's just see if they could pull it off.