This year was a clinic in how important schedule is for success. Too many top competitors (teams power-ranked in the top 25 or so) and you have the chance to rack up too many L's, plus injury rates will be higher and there is certainly a mental aspect to losing several games as well. I think this is a big contributor to what happened to the PAC-12. They had a lot of years where they really weren't that far behind the other conferences, but they just had problems getting to the end of the season intact.
Theoretically, having the opposite happen (no significant competition) should bite you, but that only seems to apply to G5 teams these days (see: Indiana).
This regular season in the SEC was great because everybody had a schedule that scaled to their performance over the past 10 years. Half the conference was in the hunt for the SEC title game with a few weeks to go. If we had the post-season of 15 years ago, this would be the ideal format. However, with the 12-team format, if you make your regular season interesting, you shoot yourself in the foot post-season.
The lesson conferences should be taking from this is to put their fingers on the scales, ensure that the top competitors from their conference have no more than 2-3 major opponents, and as many cupcakes outside of that as possible. Any mid-tiers teams that could jump up and take a bite out of one of those top competitors should have an obnoxiously difficult schedule so that they can barely field a starting lineup when they face those top competitors. If all of that sounds dumb to you, that is because it is.