Most of us who used KuCoin and other exchanges to recieve payment need to take note that there are many risks involved because of some exchanges policy and it is best to use wallet and then probably move your bitcoin out from the wallet to exchange to sell. This is usually the best practice when Receiving bitcoin.
I want to think that people who still store their Bitcoins in a centralized exchange and continue to do their transactions or just save it there either one, do not know the inherent dangers or two know about it from the stories of others and are living in a fantasy they can't lose their Bitcoins to exchange just like the others. Or maybe they are trying to be smart like wanting to save some money on the transactions fees involved in sending Bitcoins from their wallet to their exchange app whenever they have to do a transaction.