re: Is Death Valley dead?

It's a shadow of what it used to be, and currently I don't think it's top 10. I'd put Penn State firmly ahead of it.

There are a lot of factors involved, but it boils down to a few essential elements:

1) traffic and infrastructure. I think 80K in the 80's was the ideal size, roads were better, you could get in and park a lot closer, and traffic wasn't as bad. Tiger Stadium is not in a location that can support 100k for traffic, and you just can NOT fix that.

2) fans being "entitled", as such. I honestly think that goes back to point 1- when the stadium grew and they pushed parking so far away, the headaches involved multiplied exponentially. You could tolerate that when you're annually playing for the conference and national titles, but remove that and it becomes too much.

3) advances in technology. Until a couple decades ago, if you didn't go to the game your best option was listening on the radio; and then it became spending $35-40 (probably $100 in today's money) on Tigervision, on a 24" color TV.
Nowadays, every game is broadcast in HD, most people have desktops with monitors bigger than those TVs, and you can get a 50" 4k TV at Walmart for $200 (which you would have anyway to watch all your streaming services).

I remember going to a few games in the past, when I had to work until 5 or 6pm on Saturdays. I literally threw a change of clothes in the car, left work, parked out in the boonies (*what is probably normal parking today), and walked into the gate before halftime. It might have cost $5-10 for a ticket, if I didn't already have one.
You just can't do that stuff now, it ain't worth the cost and effort.