From multiple people who work at BYU, including in the AD. They went through and gave significant raises to those who deserved it when budgets increased. Not everyone deserved it.

Tom Holmoe said it publicly, and proved it privately until KY whose contract info has come out publicly: they had to make a commitment to the Big12 and the entire AD when they joined the Big12 that they intend to compete at the highest level, at every level including salaries, facilities, NIL, etc. It's not an overnight process but BYU is committed to competing and not just being middle of the road.