The contract gives the team the option of employing the player each year. Cutting the player “early” isn’t actually the team failing to live up to their end. The team said “we will pay you handsomely to give us the option to employ you at these salaries,” and most players can’t wait to sign on the dotted line cause they make nowhere near that money doing anything else BESIDES playing football.
A player holding out, therefore, IS failing to live up to his end, while a team cutting a player is not.