I would add though that the environment has changed - since 1997, dozens of schools jumped to FBS, with more joining every year, even now. Plus we have struggled to keep up with the Joneses, financially speaking.
During our big run at the turn of the century, the athletic department's budget was around $12 million a year. Adjusted for inflation, that's about $19 million in today's dollars. Marshall's current athletic budget is over $30 million. Here's where that ranked in a few conferences of note, in 2018:
C-USA: 10th
MAC: 9th
Sun Belt: 9th
AAC: Last Place ($25 million behind USF)
Mountain West: Last Place ($2 million behind San Jose State)
American East: 3rd
Atlantic 10: 3rd
Big Sky: 2nd
Big West: 3rd
Colonial Athletic: 4th
This is why I say we have to focus on aspirational thinking, because embracing reality, looking at those numbers, would say we belong in FCS.