It has no bearing on whether BYU should join a G5 conference or not.
I'm also trying to figure out your argument as it seems to argue for two contradictory points.
You have to win to be relevant, period. Doesn’t matter where you play if you aren’t in a P5.
I agree with the last sentence. If you aren't P5 it doesn't matter how many wins you rack up and BYU is a lot closer to a P5 program as an independent than they are as a member of the G5.