One problem with nepotism in the NFL is that the results sometimes work.
Kyle Shanahan is the son of Mike Shanahan, who won two Super Bowls as an NFL head coach. Shanahan coached in a Super Bowl at the age of 40. Sean McVay is the grandson of former 49ers General Manager John McVay. He coached in the Super Bowl at the age of 33.
According to the NFL's 2020 diversity report, nine of the 32 NFL head coaches in the 2019 season were either the son or father of a current NFL head coach, coordinator or position coach, and 63 of the league's coaches were related either biologically or through marriage, and 53 of those were white.