Mainly because they don't need saving. The SEC is dominating. If other schools are to survive in the recruiting wars, they have to have a shot at the title. Thus, expansion.
https://www.msn.com/en-us/sports/ncaafb/college-football-playoff-will-expand-to-12-teams/ar-AA11phbX?ocid=msedgntp&cvid=3f758894d6e2412394375fc51bbabfc7
