I feel the expanded playoffs has more to do with it. Before each regular season game was a playoff matchup. To leave yourself any margin of error you also had to schedule tough.
Now with this inclusive playoff structure teams can afford that early season unexpected loss to a Minnesota, Purdue, etc. Teams also no longer have to schedule challenging OOC opponents and have little incentive to since as long as they're in a P4 conference and have 2 or fewer losses they're in.
Defending national champion Indiana is a prime example of that. Unless you're an Indiana fan who wants to watch them beat Indiana State, Old Dominion, and Kennesaw St. by a combined score of 156-46? It's only going to get worse with an expanded playoff as what's the point when 4 loss teams make the playoffs? Schools like OSU only play 3-4 "good" teams a year and if they lose each of those games they can still make the playoffs. Makes it hard to get excited for an OSU-Oregon regular season match-up when the stakes are reduced.