Answered the question you asked already by yourself. Nobody go like make na another person dey control him money so it's definitely DEX over CEX moreover the most vital things that separated the two is when you decide to use the CEX for saving of your coin rather than just trading it for fiat when you need because that's what I use my CEX for. Saving your coin on CEX posses great risk because you are not the one in charge of the keys and anything can happen.