There are too many good reasons that 25 year olds can't be a good startup CEO. One of them is complete lack of experience and almost complete lack of knowledge on how fatigue, stress, anxiety (or health issues in general) etc affect people. Because until 25 these doesn't even resigner on you or your body in most cases.

But yes, if you meant a "good" start CEO as in "good for the startup" then yeah I would say what you said is possible or likely.