It is clear that for you cryptocurrency is only about profit. If you are willing to trust a 3rd party with your keys for 8% interest (if that even exists) maybe you don't have much invested or you are just naive. What exactly do you think was the vision of Satoshi Nakamoto when he created Bitcoin? Do you think centralized exchanges follow that vision?
If I'm not mistaking I think I read somewhere that Satoshi was ok having 3rd party standing as escrow for bitcoin transaction although this isn't centralized to some extent since he emphasis on the transaction been peer 2 peer but seems that's what brought about the idea of centralized exchange since the founder itself was ok having escrow work with the technology he has created for trust to be built. I'm not against using centralized exchange (infact I'm a new if tger biggest fans) since they make investing in bitcoin a little bit easier especially as I don't have to stress myself about trusting the users I'm transacting with.
But where it becomes a big no is trusting my funds to their care when they're as valuable as a result of their centralized server can be attack at anytime and the scammer make way with our funds without leaving any trace. Join centralized exchange but don't trust them with keeping your coins safe. Only you can do that for yourself.