Two decades ago there the SEC was not put on a pedestal like it is today. It was thought of as pretty much the same with the B10, P10, B12, Big East, and ACC. But as college football became all about TV, the SEC took a huge leap forward because no other conference provided the gameday environments on the same level as the SEC. Now the athletes all want to play in that conference and the schools they pay their coaches crazy salaries, despite owning arguably the worst markets among the Power 5. The B1G has rebounded in the last 5 years in part because the are #2 in terms of gameday environments.
Meanwhile the P12, B12 & ACC are far behind. BYU would be a school that could boost the "made for TV" football environment for any of those conferences. USC-Stanford in front of 35k in Palo Alto does not get many people excited. Nor does Pitt-Miami in front of 25k at Hard Rock Stadium. Nor do any games played in Aimes, Manhattan, Waco, Ft Worth, or Lawrence. BYU is actually capable of hosting a legit big game environment, and that would only improve if they were added to a Power Conference.