Pace of play is part of it, but it's far more than that.
Only 15 or so years ago, there were basically 8-10 college games broadcast in total each Saturday. There were no conference networks, no ESPN+, no CBSSports Network, there wasn't even ESPNU. You had 4 major networks, which only carried 1 or 2 games each, and ESPN/ESPN2. That was it, and they only carried the best matchups in each time slot, which were also subject to local blackout. Today, you can watch Sun Belt and Ivy League games on TV if you have the right cable/streaming subscription. So, far flung fans of teams don't need to travel back to campus in order to see games. I remember back then, if I didn't go to the game, having to listen to SU games by streaming TK99 online. That experience, compared to the in-stadium experience, was sorely lacking. In the last 10 years, I can't remember a game that I've missed on TV, even when we play FCS opponents.
Then add in the actual experience of watching it on TV today vs 15 years ago. Between 2000-2010, lots of people still had a tube tv, and flat panels were expensive, small, and the picture sucked. Some flat panels were still 480p, and a lot of broadcasts weren't yet in HD. I remember paying almost $2k for a 46" 720p tv about 15 years ago and thinking it was the peak of technology. Today, you can get a 60" 4K smart tv for under $500. For the same price as my 46" TV in 2007, I now have a projector in my basement that throws a 12 foot image. You get replays, closeup views of the action, and during commercial breaks you can switch to any of the other 15 games on tv to catch up on other action. At the game, you miss a lot of things because you're farther away, and during the many long TV timeouts there's not a lot to engage fans other than being blasted with dance music, flashing lights, and advertisements. At the dome specifically, you can't even check out of town scores because the wifi and cell service are awful. Yes, attending the game is partly a social shared experience...so invite 10 friends/neighbors over to watch at your house.
Add in other little things like: food and drinks are cheaper at home, your food/drink choices aren't dictated by stadium concessions, the length of games and travel time make it an all day commitment even for locals, not everyone enjoys the feeling that the football game is being played in a dance club, etc, etc.
I still go to games, and will continue to, but I get why people across the country are abandoning live, in-person sports. And honestly I'm not sure it even matters anymore. Stadiums are basically giant TV studios at this point.
