The NFL isn't actually very good at coaching in general. It's very much a copycat league that occasionally understands why things work after they've been effective.
You have to make the offense around your QB, you can't really do that with a rookie as you don't really know what they can do. It's further complicated by teams drafting QBs that have no hope of fitting in with what a team currently does.
There's probably a lot of coaches that would be amazing in the NFL that never get a shot because the league is so incestuous at the moment.
NFL -
Arizona Cardinals
Chicago Bears
Cincinnati Bengals
Cleveland Browns
Dallas Cowboys
Denver Broncos
Detroit Lions
Green Bay Packers
Houston Texans
Indianapolis Colts
Kansas City Chiefs
Jacksonville Jaguars
Los Angeles Chargers
Los Angeles Rams
Miami Dolphins
Minnesota Vikings
New England Patriots
New York Giants
New York Jets
Philadelphia Eagles
Pittsburgh Steelers
San Francisco 49ers
Seattle Seahawks
Washington Commanders