The main thing that takes time to learn in sims is the specifics of the vehicle you're trying to fly, I think it took me a few weeks to really get the planes I have in dcs and I got vr a few months after that, most work after that is rebinding everything that's changed and getting used to it. In dcs no two planes have the exact same set of buttons for everything anyway so there's new bindings no matter what you do. I'm sure if you jumped in with vr from the start it would only add a bit of extra fiddling around.