The NFL coaching gig is so much better than college because you don’t have to recruit.
It would be so tiring to travel across the country just to kiss the a$$ of some entitled 17 year old athlete, where even if you are an ace recruiter your success rate is less than 50%
But as Douglas pointed out, there also aren't usually very many quick fixes either. Even bottoming out and getting the number one pick typically entails being a disaster nearly everywhere else on the team. Plus, even when you do have a great roster, it generally doesn't last. So it's all about outcoaching the competition. I've read articles about Andy Reid when he was in Philly. He would sometimes go 3-4 days straight without leaving his office, and that was during the offseason. As good as you may be, there are coaches opposite you, also at the top of their game, who have nothing to do all year but watch your game film, dissect your tendencies, adjust to your star player, etc. There also aren't any(or many) Vanderbilts or Samfords, or just dreadful coaches on the schedule, which is why it's so rare for even the greatest teams to not lose 3-4 games, often ones you'd never expect.
Contrast that with what he had at UF, where 90% of the talent you need is within an hour's drive or two hours private flight. He once remarked about how nice it was that he could be in Pahokee to recruit a kid and watch his practice and still be home in time to catch his son's game and dinner with the family.
Both are absolute grinds. But with one, that grind is much less at certain places, and if done correctly will almost always equal great results. The other is a grind where many really great coaches have never won it all because of the parity.
He won't say it, but he should've just stayed at UF.