Any conference championship is irrelevant anymore. This year is a perfect example -- two of the four CFP teams didn't even win their conference. There is no other sports league I can think of whether it's high school, FCS, or the pros where winning your league/division means less.
I'd like to see those titles mean something, and I think the 12-team playoff will help change that. Texas high school football which to me is the Gold Standard of football playoffs is all done completely objectively, and as such there are no debates or complaints about who did or didn't make the playoff. Everyone is in control of their own destiny when the season starts.
But college football national champions are basically decided by the subjective minds of a committee. I've given my thoughts in the OP on TCU making it to the title game, but in an objective scenario neither Ohio State or TCU would have been there. And because of the loss this year that same subjective committee will use their biases to make sure no Big 12 team is part of the playoff next year whether they win the title or not. It's complete BS and it makes the college football postseason far less compelling than any other league.
But with all that said, this year TCU did what it needed to within the system we have to get there, and beat the Big 10 champion in the process. The current narrative being perpetuated by Herbstreit, ESPN, and a bunch of others is complete BS and they all seem to forget that TCU had that game against Michigan. Herbie did mention Michigan once when he said that their players didn't take TCU seriously, figured it would be an easy cakewalk win so didn't prepare, etc. It's complete BS and won't stop until we get a 100% objective path to the playoff which will never happen. But the 12 team playoff will be much closer at least.