There are now superteams, basically, so there’s not much suspense about who is going to win a conference. It’s one of two teams when the season starts, and usually you can guess correctly in August. So if you are a second tier team in one of those conferences, say a Florida currently in the SEC, or Nebraska, or Cal, what is the point of your season?
The best teams get ALL the good players because every kid wants a chance to play for the national championship, and they know that there’s only maybe 6-8 schools that will ever do so. The talent gets so concentrated that no one can compete.
That won't be the case for much longer.