Well for personal privacy and for security also. You may never know when an exchange could be compromised and aside from your crypto currencies your identity is at risk at the black market. It is going against fundamentals of BTC which is to be anonymous. Also if you are not that a so called whale which has so many BTC and could reach the daily limit of withdrawals then you are probably fine, I know Binance is giving us a 100 BTC limit you know.
Non KYC exchanges will not stick with non KYC policy forever. They can change policy when more regulations implemented by governments. You just don't know when they do it.
On exchanges with KYC but have free KYC with limitation, if you reach it, you will have to complete your KYC to be able to use it again. If you fail, it's terrible. So if you use centralized exchanges, the best approach is complete KYC first. Then you won't have nightmare later.
If you seriously against KYC, let's use DEX.