The NFL's head coaching carousel is constantly revolving, with several openings cropping up each offseason. In 2021, seven teams hired new head coaches, most of whom came from the ranks of pro coordinators and position coaches.
The lone exception was the Jacksonville Jaguars' hiring of Urban Meyer, who last coached Ohio State in 2018. That came one year after Matt Rhule was the lone college coach hired for an NFL head coaching job and two years after Kliff Kingsbury made the only jump from college to the pros.
While innovative college coaches do occasionally get opportunities in the NFL, teams mostly interview prolific pro coordinators and/or head coaching retreads.