However, we ought to also know that part of the advantages of Cexs is the ease of regaining access to one's account if password is lost or forgotten. This isn't the case with private key or seedphrase of private wallets. Once those are lost, they're lost forever.
I don’t think the topic is about which one is safer, personal wallet or CEX. It’s about the importance of sending coins from your personal wallet to a CEX rather than sending it from another custodial service.
I can think of two scenarios where this can help: In some cases and for different reasons a centralized exchange may ask you to provide a screenshot for the wallet from which you sent the coins.