Kids would rather play against Michigan, Michigan State, ASU, UA, Stanford, USC, Cal, ACC schools, B10 schools, etc etc 5-6 times per year, than play 8 MWC games and maybe 2 big P5 games as BYU used to do pre-2010.
The formula has changed. going back to a G5 now means BYU goes back to a totally different landscape than it as in 2010. ie--Ther e is no going back. that place no longer exists.
Also, BYU needs more capital in order to keep up with benefits offered to athletes. COLA and stipends. That matters. USU has to get money from the state of Utah in order to offer it, which is pathetic.
So BYU won't keep up without P5. But it has options to keep it closer as Indy, 2018 notwithstanding. Losing widens the gap more than Indy does.