The Rent was pretty awesome at it's peak from 2007-2011 and that's coming from someone that was making the bus trip. The atmosphere in and outside the stadium was fantastic for students, alums, and fans.
The only negatives were 1) the bus ride itself was a time suck for students, but the student section was still full anyway so hardly a negative other than people's time, but 2) because of the bus, students left after the 3rd quarter most of the time to get back to campus and beat the bus line.
The problems are obvious and have already been stated here: the team needs to win, and not just win, but be good, which hasn't been the case in 13 years, and beat recognizable opponents (separate discussion that's been litigated 1,000x).
Secondarily, though, student habits around sports are not the same as they were a decade ago or even 5 years ago. Even if the team was just pretty good, I question how likely they'd actually go into the stadium.
I'm not going to act like I know the modern student that well, but anecdotally it feels like today's class of students at UConn are more studious and choosy of how to spend their time. "Why spend 6 hours in East Hartford to watch a 7-5 football team, when I can just spend 3 hours in a parking lot partying then go home." Then the supposed shutting down of much student tailgating post COVID doesn't help the situation either and further dissuades students from making the trip at all.
Anyway this is much ado about nothing in my opinion since I do not see a world where a stadium is built on campus unless something dramatically shifts and I'd give it like a <5% chance.
It took UConn Men's Basketball winning not 1, but 2 national championships back to back for the State and Athletic Department to get serious about renovating Gampel and I'm still unsure how substantial the changes will be. That's the type of mountain you are talking about climbing here.