Well in principle you should't keep your coins in cex, and if you are tech-savvy enough, obviously self custody is the best solution. And everytone should try to learn it if they haven't yet.
But i wouldn't recommend self custody to my mom for example who barely understands how to work with a different browser. I am pretty sure that he would lose the private key and the backup if she used cold wallet. And if she used desktop wallet i couldn't guarantee she wouldn't get hacked at some point.