Truth is that whole wheat just doesn't rise as much because it can't.
The whole part of whole wheat is bran. Wheat bran is sharp. Which r is not great for rise since those sharp little bits are poking holes in the bubbles that make bread rise. It's a pain in the ass.
Best solution I found for true whole wheat that didn't involve adding things in that would make it a blend instead was switching to a gentler kneading method and not working it beyond the bare minimum needed to get gluten going.
Check out King Arthur flour's website though, they have whole wheat recipes that work very well because they've been built around the reality of it from the begging beginning