Why doesn’t Dr. Carson try at the mayoral level, then the governor level, before he tries at the presidential level?
Even if we have a collection of nitwits currently at those levels, it doesn’t negate the need to show competence first in large-scale organizational management.
About the only people that I would consider prepped to slide into the White House as a first governmental job would be, for example, whomever is running Ford.
George Washington didn’t serve as mayor or governor. Granted, he was a military leader.
At his age and level of lifetime achievement you go for it all.