its not an issue of market size, its an issue of revenue sharing
Revenue sharing is a direct function of market size. If you have more revenue, you have more to share. If you are in a small market its hard to generate revenue because your sources are limited. I'll give an example.
Alabama. Stadium Size 100.077. Tuscaloosa Population 111.338. Metro Pop. 277494.
USC. Stadium size, 77,500, Los Angeles Pop 3.821 mil. LA metro 18.42 mil
Because of the differences in market size, it puts Alabama in a bad situation. If they piss off a significant percentage of their local fans their stadium is empty. No way around it. If some change loyalties they are boned. A few bad seasons and they are looking at half-full stadiums
For USC they could literally alienate millions of fans and not care. They could suck (as they have) for significant periods of time and still not care. Because there is always gonna be someone in line for those tickets. USC could literally piss off 5.1 million(population of the whole state of Alabama) people in their metro area so much they'd never go to another UCS game and not care because there's another 8-9 million they can sell tickets to. UCLA has sucked at almost all sports the last 2 decades for long stretches and they still can sell out games. Sharing the market with USC because the market is that big.
When you have a small market you can do well in good times. But, when it gets bad and folks start leaving you have no one to fill those seats. USC can have a terrible team and folks will still come to their games to meet all the celebs that have nothing to do with the sport being played.
LA is an extreme example of this. But it applies down the chain. There is a much better chance of there being a reason other than the game to go to one in say, Nashville than there would be in say Columbia, MO. If Vandy ever had a sustained run of being good they will quickly become a problem because of that. All the conferences on the West Coast spent the last year fighting over UNLV for that reason alone VEGAS.. They backed up the Brinks truck to UNLV to get them to join their conference BEFORE this season happened and what was the fallout? UNLV turns around and has their first appearance in the top 25 ever. UNLV has won more than 9 games twice. 11 this past season and 11 in 1984 (all those wins were vacated for the 83 and 84 seasons for playing ineligible players). SMU the only football team to get the death penalty is rising from the ashes because of NIL... they got the Death Penalty because they instituted NIL 50 years early. Now DFW has a college team to get behind again.
Market matters and you'll see it more and more over the next few years as all of a sudden teams you never really thought about pop up. Some to look out for are GA Tech and GA State. If either of those 2 pops off it will hurt UGA immensely because it will cut them off from all those homeless Atlanta fans. Atl is a very volatile market because the majority of the pop isn't even GA born. They are more likely to identify with a decent team around the corner than one almost 2 hours away. People at heart want to support their local team because its right there. It's just human nature. Imagine if the Vols never hired Danny White, Barnes, Vitello, Heupel, and UTC goes on a 10-year rampage where they win FCS 3-4 years go FBS and are all of a sudden a top 10 team. The next few generations become UTC fans instead of the Orange and white. Because Knoxville is not a big enough market to stay loyal to a bad team for decades places like Chicago, LA, and New York have a big enough pop that the die-hard fans can sustain you. There are more die-hard USC/UCLA fans in LA County than there are people in Knoxville, heck, probably the state of TN. Market share matters because math is undefeated.