Parity? Not so much, unless you're comparing apples to apples. In this case, the apples are the Power 5 conferences and Notre Dame. The rest of the field would be the oranges.
CollegeFootballPoll.com calculated the power of each team in each conference, then provided an average for each. By the measurement, the Big Ten slightly tops the SEC in projected power in 2018 by 78.92 to 78.88. The PAC-12 comes in last among power conferences, but still has an average of 76.73. The top 5 conferences are as tight as they have ever been, even if the SEC just keeps on winning championships.
However, the separation between the Power 5 and the rest of the field widens dramatically at the outset of the 2018 season. At the end of last season, the difference between first (ACC) and worst (Sun Belt) was 17.17 points. At kick-off this year, the average separation between first (Big Ten) and worst (Sun Belt) is 26.94 points.
The difference between the lowest-ranked Power 5 conference (Pac-12) and the top-ranked conference in the Group of 5 (Mountain West) is a whopping 19.70 points.
But just as there is parity within the Power 5 ranks, there is also tremendous parity within the ranks of the Group of 5 schools where less than 6 power points separate the MWC from the Sun Belt.
As for the Independents, the average is inflated by Notre Dame's power of 92.81. Remove the Irish from the equation and the rest of that group - Army, BYU, Liberty, UMass and New Mexico State - would average just 60.39 instead of 65.80.
Here is how the conferences and divisions are expected to rank for 2018.