Yeah, it has never been a big thing in the NFL, more so an unwritten rule not to use "'s of past greats on the team.
Unlike other sports where it is really big.
While some other NFL teams, Giants, & Bears come to mind, (they have the most according to Google) have retired numbers, they have been few. "Dallas Cowboys, Las Vegas Raiders, Houston Texans, Jacksonville Jaguars, and Baltimore Ravens don't have any"
Side note, "Reggie White is the only player to have his number retired by two teams: the Philadelphia Eagles and Green Bay Packers."