Tomcat I fully respect your stance against using Steam. Yeah, I was more referring to a VR headset with a wire- like SteamVR.
It would be nice if there was a universal one that just works. I doubt it would be easy to make one, however. How much goes under the hood of a headset? The lenses on the Oculus Quest 2, at least, magnify so much, that they can burn in the sunlight- and I'm certain there are other crazy aspects we don't even think about. Most likely, internet connection is a must due to the use of a gyroscope, and then whatever screen(s) you need to give an image. I say screen(s) as double screens could offer a 3D image fit for theaters. It would be pretty stellar, IMO.