Another consideration:
One reason Trump did well in 16 is that he was not Hillary. Many voters went for Trump because he was NOT Hillary.
The reverse happened in 20, many voters (I know some) just couldn't pull the lever for Trump. Unfortunately, it was personal, they hated his inability to act presidential. (I do not defend the reasoning, I merely report it. I voted for Trump.)
In 24, we can expect RINOs to run against Trump, they see this as their big chance. (Thinking Willard, Cheney, Kasich, Jeb and etc as possibles.) I also suspect they might not be above a third party megaloss, just to feel important.
DeSantis will have greater appeal to disaffected GOPers and Indies.
Trump or nothing. Accept no substitutes!!1
Spot on, from my own experience as well.