By that criteria the PAC and ACC minus Clemson aren't power conferences
Florida State is a National Title Contender once they get their act together. You can probably say the same for Miami.
In the Pac12, you got Oregon, USC, and Washington. UCLA hasn't done crap in two decades but they have a history of competing at high level.
I planned on making a very long post about it. You can kind of put CFB into multiple categories:
Current National Title Powers (Alabama, Clemson, Georgia, LSU, Oklahoma, and Ohio State are really only programs that fit this bill).
Blue Bloods\Historical Powers that are down: Florida State, Michigan, Miami, Nebraska, Notre Dame, Penn State, Tennessee, Texas, USC
Up and coming programs (Not traditional powers but have been competing at higher level lately): Oregon, Utah, West Virginia, Virginia Tech, Wisconsin
Mid-tier programs (they can compete for titles but won't do it consistently and generally are mid to low tier. All have the potential): Auburn (I can see argument to put them in Blue Bloods/Historical Powers that are down category), Arkansas, Arizona State, BYU, Colorado, Georgia Tech, Iowa, North Carolina, Ole Miss, Pittsburgh, Syracuse, Texas A&M, TCU, UCLA, Washington
Once you get outside of these categories, it is hard to make the case for anyone being in the mix of winning a title. I know some of the teams listed haven't competing in over 25 years but there is some history in their program of competing at a high level. There is another category of note:
Once great Blue Blood programs that would no longer be considered elite by anyone: Ivy League (historical best league when you count all-time titles), Minnesota, Army, Illinois, Vanderbilt, Sewanee. This is a list of teams that won National Titles or competing at a high level in the past but have NO hope of doing it today. For example, Vanderbilt was a dominate program in 1900, 1910s, etc. but is clearly a bottom feeder today. Army has two national titles and three Heisman winners. The Ivy League squads (like Yale) have more National Titles than any of the blue bloods but could not compete in modern CFB. Minnesota and Illinois both have 5 national titles each but this was before 1940. The chances of them make a playoff is very low.