I googled them and yeah they have an official arcade version, which are basically a HTC Vive headset with the Vive controllers. Apparently according to several reviews, the tracking is horrible, the headset can't be tightened properly, and the choice of songs is miserable, and they don't seem to support 90 or 360 degrees. And yes of course you are right, you could just render it on a screen, in fact, if you are playing PC VR, it always renders to your monitor anyways. When I have friends over, I always have the view mirrored to a projector for "party mode" - just like in the arcade - which allows spectators to enjoy the show as well.

The real question is, have you played it in VR? You don't "need" VR to play but it's absolutely a different experience than just looking at a screen, for the reasons I stated in my previous comment. It's not even comparable when your brain _believes_ (to some degree) that you are actually inside the Beat Saber world.