If Ron DeSantis somehow loses to Charlie Crist, he's finished with elective politics. He'll never run for anything again.
I'd also add that DeSantis losing, and we'll know early as Florida tends to count their votes quickly, would be the harbinger for a massive GOP catastrophe across the board. Everyone with an (R) after their name would be in serious trouble. We'd be looking at a Blue Wave midterm sweep.
At that point, it wouldn't really matter who runs in '24. There wouldn't be much left.
American politics are filled with examples of candidates losing and bouncing back, come on now.