After that -- you have a huge group of 2nd tier teams who are waaaay back of those 3 teams. Teams who can win their division once in a while. Teams who can even reach the CFP once in a while. But competing year in and year out for national titles isn't happening. They may have a 1 or 2 year stretch they strike gold with a few recruiting classes and compete nationally, but year in and year out is not happening. There are ONLY 3 teams who never have to rebuild is Bama, OSU and Georgia right now. They have five star recruits sitting behind five star recruits for their turn to play.
Don't get me wrong -- it isn't that Bama, OSU and Georgia are the only schools who can be elite. Texas can be elite with the right coach. USC can be elite with the right coach. One of the Florida schools could be elite with the right coach. Why those schools? Because they are located in the most talent rich states in all of CFB. They don't have to rely on convincing every blue chip recruit they sign in every class to travel across multiple states to play football in the Midwest. And I can tell you right now -- the kids who have grown up in the Midwest, Nebraska is way down the list of teams in the B1G they grew up watching.
I have zero against Nebraska, but with their location, now playing in the B1G so all their games are in the Midwest now, with no national rivals, playing in the weak conference of the B1G -- I shouldn't say never, as I know better (doctor told my wife she'd never be able to have a kid, yet she has been able to), so it will be next to impossible to compete on a yearly basis with even top B1G teams, let alone, the nationally elite.