This might be a wildly unpopular opinion, but I personally feel if somebody requires VR/video game to be bolted onto exercise in order to stick with it, they're probably not going to stick with it.
I also can't see how the people that use VR/video games as their primary/sole exercise source don't transfer the supposed monotony of exercise which they are trying to avoid, over to the video game, eventually.
I run and go to the gym almost every day and have gotten it into a habit which reinforces itself (wanting to cover more distance, faster pace, heavier weights). I don't think I could replace running, swimming, the gym with a VR game like table tennis or Beat Saber and get anywhere near the same intensive workout, and I doubt I could play these games daily for more than a month without just getting fed up of the game, as you would with any standard video game.