My guess is the Big10 and SEC are arguing that, based on the media deals they have gotten, the total media value of the CFP playoff is higher with the best overall teams rather than on autobids. Whoever buys the rights to the playoffs in 2026 and beyond will pay more for the best teams overall and that means we can distribute more overall (every conference will get a baseline to get everyone to agree and then more based on appearances).
While it would maximize profits now, I think that would end up declining interest in CFB overall. As more and more schools get left out, less interest overall will mean less eyeballs which will mean less revenue for media deals in the future.
If I'm ESPN, I'd get be begging them to include more and more autobids for more conferences. The best case for them isn't more interest in the SEC, its more interest in the AAC and MACtion. A rising tide raises all ships. Yeah, they might make less now but it sets up for a better stabile future.
It's why horror movies are always going to be made. Spend $1mil on a movie, make $10mil opening weekend, sell it to a streamer and boom easy money. Which you can then spend on your bigger movies to chase the bigger profits. (Ok this analogy isn't perfect since we haven't seen a Dial of Destiny type flop in the CFB media deal yet but it's coming)