evidence that they could be successful against stronger competition. Utah got its shot, and struggled for several years.
BYU's Indy schedules are stronger, but not quite up to a P5 level, and the teams have not done well against those schedules. As in, BYU has been showing evidence that they can not do well against the tougher schedules.
That is a bad situation for a team trying to get an invite. A team with great records against G5 competition has a better shot at the Great Invite than a team struglling against tougher competition. Remember Bronco's string of 10-win seasons? That was the point where BYU was best situated to get a P5 invite.