Bookkeeping sometimes take precedent over playmaking. Some say the salary cap isn't real, yet organizations are forced to cut players every offseason in order to be salary-cap compliant. Other franchises benefit as a result.
For example, the Tampa Bay Buccaneers released longtime left tackle Donovan Smith last offseason. He signed with the Kansas City Chiefs and protected quarterback Patrick Mahomes' blind side all the way to a Super Bowl victory.
Tough decisions are made regarding individuals based on their contract status. Whether through coaching changes, exorbitant cap hits or disappointments, proven veterans are cut loose for others to sign.