That's not entirely correct. A committee member, on Twitter, clarified a position stated by Jerry Palm (CBS bracketologist) that even though Palm said the committee only uses NET rankings as a method to look at how they did against what quality of opponents, they also look at the NET rankings themselves and other efficiency metrics for assessing teams and placing them in the bracket.Technically Villanova is not “ranked” ahead of Auburn in the NET as the NET is not used for rankings.
The committee does not use your net ranking in their evaluation of your possible seeding. Instead, they look at the net ranking of the teams you beat and lost to.
That being said, Auburn is “ranked” 6 in KenPom, even though they have just one loss because advanced metrics like KenPom & Net look at more than just wins and losses, but also how you played in those games.
Advanced metrics are useful, but humans monitoring actual wins and losses is useful too.
As for why the NET rankings, Villanova is ranked higher than Auburn because Villanova has been a more efficient team than Auburn over the season (more impressive wins against a tougher overall schedule). Results-profile-wise, Auburn leads the pack.