Utah's schedules have been WAY more difficult than BYU's over the past 4 years.
Kyle has won 85 games (he was the head coach for the Fiesta Bowl) and Bronco has won 90. That is overall wins, NOT just favored games. And 'favored games' is a terrible metric.
BYU plays far more patsies (more favored games) and way weaker teams than Utah, even in 'favored games'. It's not apples to apples.
Utah finished #21 and #22 in the nation, respectfully, last season and had the same win loss at the end of the regular season as BYU. BYU wasn't near the top 25.
It all had to do with SOS. i.e. Utah's schedule was WAY more difficult.
What Bronco and crew would have done against Utah's schedules the past 4 years would have been embarrassing. And Utah would have dominated BYU's schedules the past 4.
And, NO, Bronco would not be the coach right now had BYU been invited to the PAC 12 in lieu of Utah.
You can't only win 3 games a year and still be the coach. And that is what would have happened in that scenario. Bronco is 3-22 against team who finished ranked. And it's not pretty with opponents who simply have winning records either.