You said: "I'd love playing top teams week in and week out in meaningful games."
The Pac12 is not "top teams." They're mostly middle to low tier P5 CFB teams, with a few (1-3) very good teams.
Also, I actually think BYU's strength of schedule this year is on par with most P5 schedules. Outside of the State of Utah, (even in the other parts of Pac12 country) BYU is viewed and discussed as a P5 team. I feel like BYU fans in Utah have an inferiority complex sometimes, along win an inflated view of what Utah is right now just because they're in a club with some cool kids, so to speak.
"Stand with anybody that stands right, stand with him while he is right and part with him when he goes wrong."