I do think that BYU has been surpassed by teams that used to be its peers. Utah went to the PAC-12, and has subsequently won seven rivalry games in a row. They have a significant revenue advantage. They have surpassed BYU in recruiting, depth, exposure, and relevance.
TCU joined the Big-XII- and has likewise surpassed BYU in national relevance.
I do not think that BYU is dead. I DO think that BYU has become significantly less relevant- and I don't believe that it began when Kalani was hired. Bronco could see that things were not getting better.
One could easily make the argument that USU has become more of a rival to BYU than Utah currently is. And Boise State?
As I said in my post, the question that I have is "Was it just bad luck? Was it all beyond BYU's control? OR did BYU make mistakes, along the way, that seemed like good ideas at the time- but in hindsight, turned out to be mistakes?"