Recruits want facilities, uniforms, exposure, and all the rest. It's silly, but being able to make a social media post about palatial locker rooms or bleeding-edge practice facilities might be the difference between a commitment and a miss...
There's definitely something to be said for BYU's cautious "We don't spend money we don't have" approach... But we're very much in an arms race, and conference realignment is by no means over.
If BYU doesn't want to end up on the outside looking in, it would behoove them to treat power-conference membership as an investment and prioritize spending on their money-making sports.