TL;DR The behavior of students today is not all that different from a decade ago, non-students need to turn out better, the team needs to keep playing well, and as OP noted UConn needs to accommodate students better. Students aren't the problem.
I was a student when The Rent and UConn Football was at it's peak and even then when the team was good and environments lively, students left after the 3rd quarter so the fact that it's halftime today highlights not much has really changed.
It is just a long day and a huge amount of time dedicated to one thing when you consider the time to get to the game, tailigating, then the game itself, then getting back to campus.
Now being years removed the biggest issues of which some have been mentioned already and some have not:
1. The games are too long. That game against Temple last week was comically long, but it's a CFB issue in general. NFL games are usually about 3hrs, CFB closer to 3 1/2 hours and that's on average. The games need to be tightened up to get closer to 3 hours. It helped MLB massively getting more action in; TV timeouts are stupid long.
2. It sounds like some combination of The Rent, UConn, and local police / government have become more hostile to the student tailgating experience. I remember going 7 years ago and seeing a giant frat / sorority block party with DJs in the parking lot and it was fun. Now it sounds like those in charge are more restrictive of what's OK
3. Winning 3 games doesn't over turn a decade of not just bad football but so embarrassing it tarnished the brand severely. You don't turn a cruise ship around on a dime, it takes time and repeatedly building back trust and rapport, and that's not even mentioning who and how good the teams are they beat. I am not complaining, winning is winning, but let's not act like beating Buffalo is the same as beating a team these kids were also looking at during their college admission process (e.g. Cuse, Maryland, BC, Rutgers)
4. The FOMO piece mentioned earlier is big. If you're a student and see the Rent is empty, why should you care? The state needs to make the environment a place to be along with the team being better (which has already started to happen) to make it worth investing time. Once you get 30,000 of the adults and families showing up and the team keeps winning then you have something valuable that someone would want to invest their time.
Students are the last thing I am thinking about at the moment, but I do think OP has some great ideas and a lot of them are really easy, with the caveat UConn does not own or manage the property so they have to play by the state's rules which likely limits a lot of what they can do.