Kucoin and Bybit Livechat support are very quick according to my experience. The issues and my queries were solved within 10 minutes maximum. My worst support experience was with Bittrex and Binance. If you have a quick issue you would like solve ASAP, be ready to be disappointed. The slow response rates of supports from both exchanges made me to give up on waiting.
As for KYC, I have only verified with Binance so far but my account got verified in just a few hours.
I started using Kucoin a little more intensely in the last few months. I am completely dissatisfied with them.
Their platform is very slow, they have many derivatives and moving between them sometimes knows to tire me. I still not fully understand his UX design idea and by what structure they made a schedule of contents.
The android app looks almost the same as the Binance app.
About their support, two years ago I had some communication with him and then everything was fine and we solved all the doubts very quickly.
Binance if we know they have the largest volume, the most users, most orders... works much faster (for me)
I also use CEX.io it is one of my first exchanges, and somehow I got used to them. but they have none of the chart indicators so for daily trading, you must use another service.