You comment on no one leaving early for the draft is just wrong. Half the NFL draft are early enteries. If the statement relates to elite QB prospects, then it makes some sense, even though you do have the Brad Kaaya types every year.
Personally, I think he stays another year. First because he hasn't taken the same incremental jump this season as last season. Second, because I think it is a good draft year for QBS. Of course he has to consider if he can take another year of getting hit too many times when he drops back.
However, I have way more optimism on his prospects to play in the league than you do. The physical tools are there. The combination of size and arm strength are going to get him serious NFL looks. Surely, you read last week's post were CT was projected as a late first round pick going to Washington. I don't think that will happen this year, but I wouldn't be shocked at all to see it happen after a good senior year. Scouts care about how you project in the NFL way more than your production in college. Otherwise, JJTBC would be a first round pick.