Smart people schedule down. Schedule down. Don’t be stupid.
ACC and SEC teams play eight conference games, and both leagues allow teams to use the penultimate Saturday of the regular season for non-conference games—typically of the wet, hot garbage variety. This way, Auburn and Alabama aren’t wearing themselves down before playing one another in the Iron Bowl. Florida State gets a less rigorous opponent the week before it plays Florida. (And vice versa.) Ditto for Clemson and South Carolina in some years. There is nothing more sacred about the Saturday before Thanksgiving than there is the third Saturday in September, but these two leagues apparently were the only ones to notice.
These games serve several purposes. They allow teams to enter huge matchups less beat-up, and they often allow each league’s teams to be as fresh as possible before playing Power 5 non-conference opponents. Remember, beating those teams helps the conference’s strength of schedule. Winning these games also allows the leagues to play much more interesting conference games in September weeks when they might have had a lineup of mostly non-conference stinkers. It is not an accident, by the way, that an SEC team has won nine of the past 12 national titles and ACC teams won two of the other three.
https://www.si.com/college-football/2018/05/07/pac-12-schedule-larry-scott-playoff-rankings