For me the most secure exchange is kraken. The best in terms of fees is Coinbase - for withdrawal it is almost 0 fee. The worst exchange without any doubt is Bitstamp. The fee is enourmous 0.005BTC. And each week they send me new emails asking insane things, to prove the origin of my bitcoins and fiat, by sending bank and credit card statements, pool statistics, and many other things. I stopped using this hilarious exchange several months ago.
I think FTX is better than Kraken in terms of fees. I have used it several times without any KYC and I haven't faced any issue there. Though the limits are very small for non-KYC users the service is good enough to continue using them. I also have a KYC verified account in Kraken but didn't use them too much actually. I started using another exchange bybit.