YEah BYU has issues with how it handles and supports athletics. Probably too much bureaucracy and restriction. We all know it. But the biggest issues are 1) Recruiting and 2) coaching.
IF BYU got into a P5, we'd see #1 helped, but it still would rest on #2 as well. But even if #1 improved, poor coaching would mean fewer wins. Lots of P5 schools with great resources stink at football, so $$$ is not a cure all. Gotta control what you can. It starts with #2.