You literally read nothing of what I said.
"Only in the world of FBS CFB does this argument exist"
Yes. I know. That's literally what I said. It's the most unique regular season in sports. It means more than any regular season in any sport, anywhere. It's one of the very few things that make CFB unique. So why water it down? We have essentially meaningless regular seasons in professional football, where an average team can get in and get hot and win a championship. We have it in college basketball, although of course the tournament is great, but that's their thing. Why go that route in college?
"If a 9-3 team gets in and goes on a run to win the title then they deserved/earned it"
Again, exactly what I said. I don't want a 9-3 team to get into anything. Why? Because the 1st, and 2nd, and 3rd losses should be so colossal, they should eliminate them from championship contention. Just the example I gave. For example, let's talk 2022. What if we go into Clemson 9-1, and they are 10-0. In a 4, or 6 team playoff, that game almost certainly have championship implications. The loser is probably eliminated from the playoff, or really close to it. The intensity would be incredible. If you have a 12 team playoff, yes the game would be great and very intense, but if you lose, eh, not the end of the world, we got a shot to get into the playoff. It's not the same. It takes away from the magnitude of that game. AKA diminishes and waters down the regular season.
So I do think an expansion is good. I love football, I love football games between good teams, I love important games late in the year. Another playoff game, or two, would be great. But 12 is too many. I think 6, or MAYBE 8 is the best route.
Lastly, your "9-3 team gets in and goes on a run" is very, very unlikely to happen. Look at the current system. The #3 and #4 teams get blown out annually. Cincinnati was the 4th best team last year. They lost by 100 to the team who didn't even win the championship. You think the #12 seed is going to go on some magical run and win 3 games in the playoffs against Bama, UGA, and Ohio State? Stop it. We're still going to get the same programs wearing the crown at the end of the season, but we're going to water down the regular season just for a couple more blowouts in playoff games.