With an 8-team playoff, we are guaranteed of having 2-loss NCs. Perhaps a 3-loss NC. Guaranteed, on a long-enough timeline. We are guaranteed of having two schools play each other 3 times. Auburn and Georgia would've possible done so this year, in an 8-team playoff.
I feel like if your favorite schools hasn't experienced some top-5 games with a rival in late November, you aren't able to understand the point here. Florida and FSU played each other in late November and were both top-10 teams for over a decade straight. Those games were massive, yuge battles because everything was on the line. OSU-Michigan is similar, as is the Iron Bowl. Lump USC-ND in there if you wish (although not in late Nov).
Those season-ending games lose all importance with an 8-team playoff. If both are in the top 5, then who wins largely doesn't matter. Why in the holy hell would we want to circumcise the biggest regular season games???