I think there are a few problems as this topic has come up before.....and this list is not even taking COVID into account.
1. College football is the only sport I am aware of when the date and time of the game are not known until 6 days in advance. This matters as....
2. People used to buy season tickets because the only way you could get your hands on the big games were to buy season tickets. If I wanted FSU tickets, I had better be a season ticket holder. But, because of #1, I don't even know if I'll be able to attend that game, need a hotel, etc. There's a big difference, depending on where you live, in finding out that the game is at noon or the game is at 7:30.
3. TV. Not HDTV. TV. A lot of people will argue it's the quality of the picture and broadcast that HDTV brings, but I believe it's the choices that the proliferation of networks has created. I can get every single game I want to see on TV. It used to be if you wanted to see your game, you had to go the majority of time. And you might be able to see your game, but ABC covered games regionally, so you wouldn't see Ohio State-Michigan State, USC-Arizona, Oklahoma-Texas Tech, etc. You see it all now. I can see Wake Forest play the Citadel now if I want to. ABC, CBS, NBC, ESPN, ESPN2, ESPNU, the SEC Network, ACC Network, Big 10 Network, FOX, FS1, etc. I can watch 10 games at once. Now, it can be a sacrifice to go see your game because.....
4. Truth be told, a lot of people enjoy good football sometimes more than their team. I have had this happen in the stands. When Florida is playing Vandy, more people are checking their phone or the scoreboard to find out what Georgia is doing, FSU is doing, what's the upset alert of the day, etc, than there are people locked into their game. That's actually in the stadium with a game right in front of you. I used to NEVER, EVER, change the channel while my team was on. I'd be lying if I didn't admit that I'll flip back in forth to other games if Oklahoma is playing Texas while Florida is playing some chump they're up 4 TDs on.