because they were never really great as a program anyway (except a couple of years). They're good, and not finished as a program, but they won't be dominant in the Big12. They don't travel well as a program, their fans are fickle, and they don't have as deep of NIL pockets compared to BYU. They also have recruiting disadvantages because Utah isn't a desirable location for folks unless they are LDS, and now BYU is a legit location for LDS kids.
They'll trend down in the Big12, but no, they aren't out of the picture completely. Just neutered.