I think that is simplifying it a little. TV markets aren't the big key any more because conference networks can't force cable subscribers to pay a monthly fee. But, major media markets do still matter. A good Houston or Tulane or San Diego St or UCF team in a P5 conference would be a bigger draw than a good ISU team. That's just reality.
I disagree that a good G5 team is a bigger draw than even a bad ISU team.
2015. ISU goes 3-9 with a dead man walking at head coach. Averaged over 56k, selling 91% of the stadium’s capacity.
Same year. Houston goes 13-1, finishing #8. They’d moved into a brand new on-campus stadium the year before. They averaged under 34k, about 83% capacity.
2017. UCF went undefeated, finished #6, and drew under 36k, also 83% capacity.
2019. Cincinnati goes 11-3, finishes #21, averaging under 32k, which is 79% capacity.
Point is, these teams couldn’t generate much interest during really, really good seasons that they’d be quite unlikely to replicate in a P5 conference. If they can’t generate significant fan interest in a good year, they’re probably not going to when they’re going 6-6 in P5. They’d unquestionably get an attendance bump, but those additional fans probably wouldn’t be rooting for the home team.
TV markets
only entered the conversation around conference realignment because conferences wanted to force as many cable subscribers to pay the fee as possible. That’s it. A large local population presents an opportunity for schools to build a fan base, but it’s not a guarantee of a fan base.
On the other hand, all those schools do out-draw KU…