Only time I see it making sense is when you are converting from Fiat to Crypto. Then you should be withdrawing your coins right away to your wallet. Most of the decentralised exchanges will let you trade directly from your wallet, are cheaper, safer and easier to use. There are lots of very good ones. (I can post some reviews of DEXs if people are not aware). So, why do people insist on using centralised exchanges and leaving their coins on there?
Centralized Exchange Horror Stories
https://medium.com/totle/centralized-exchange-horror-stories-3d774109c50c