It's more the approach to the game. Guys like Koepka, Dechambeau, etc are a much different cut of cloth than McIlroy, Spieth, Thomas, and Fowler. It's almost like a goon approach where you get huge and just try and blast the ball a million yards off the tee without caring where it goes. Tiger showed how bulking up that much can really cause stress on your body with the intensity of a pro's swing.
But hey, like you said, it's working for them so not hating. Definitely thought higher of DeChambeau' after seeing some of his interviews and emotion over the weekend.