TH and the BYU Admin did a pretty amazing job of making being an Independent a successful venture.
Independence, by itself, didn't guarantee anything. Independence could have been a train-wreck on a train-wreck with different hands at the throttle.
The choice was to stay in the stable security of the MW cesspool, or to take a leap of faith and either crash-and-burn or soar in the rarified air above G5-land.
Regardless of getting into the B12, I would say BYU has made as much of Independence as we could have hoped, and it's been far better than MW-purgatory.
If somehow we never get into a P5 conference -- if we can at least get a scheduling alliance with at least one P5 conference and also secure a better bowl situation (probably through alliance with a conference) -- we could probably survive indefinitely as an independent and possibly even thrive. It would definitely be a tough-row-to-hoe, and exhausting for the AD, but possible.