yes, it can be said that the Uniswap platform has experienced great success in the market especially for 2020. there are many new and old projects listed on the exchange. although the withdrawal fees there are expensive the trading volume there every day is always increasing. This illustrates that DEX platforms like Uniswap are getting positive points in the industry cryptoqurrency.
withdrawal fees on Uniswap
NO.. 
I know for sure that you do not trade on Uniswap
Couple of years ago DEX wasn't much popular than right now. People couldn't use it properly because lack of liquidity. That's why many DEX died also. But After Uniswap rise the whole picture is change about DEX exchange. Many promising DEX also coming now days which have lots of liquidity, volumes and much security like Uniswap. The way Uniswap going, i wouldn't surprise if it will take place over Binance.
A couple of years ago, it was absolutely safe to trade on centralized exchanges.There was no regulation or useless "Know Your Customer" procedures.https://www.okex.com/support/hc/zh-cn/articles/360051787072-OKEx%E5%85%B3%E4%BA%8E%E6%9A%82%E5%81%9C%E6%8F%90%E5%B8%81%E5%8A%9F%E8%83%BD%E5%90%8E%E7%9B%B8%E5%85%B3%E4%BA%8B%E4%BB%B6%E8%BF%9B%E5%B1%95%E7%9A%84%E5%85%AC%E5%91%8A
Large cryptocurrency exchange for 21 days does not withdraw crypto coins of clients