If BYU in 2021 loses just to, lets say ASU and USC, they will be a top 15 team
with wins over numerous quality opponents among P5 and G5. BYU will be disrespected and downgraded, I'll grant you, but not as dramatically as you think.
BYU was top 15 last year with 1 loss, and wins over a bunch of middle to low tier teams.