The NFL format is okay IF AND ONLY IF you play everyone else in your division/conference.
In the NFL, you play a bunch of teams twice, and possibly a third time in the playoffs.
You also have a bunch of non-division winners in there.
College football can have leagues/conferences or conferences/divisions, but the #1 most important difference is to keep the playoffs exclusive.
Even under the umbrellas of bloated, super conferences (B1G & SEC), we can keep the divisions regional/traditional and only champs get in, or champs and 1-2 total at-large teams.
The sanctity of the regular season is the key. It will either be reinstated or ignored to the detriment of the sport.