It also comes at a fraction of the cost. Four headsets plus a cluster of SGI workstations to run them would probably set you back a million dollars. Today, you're looking at about $10,000. 100x improvement in cost. Hell, quantity has a quality all its own.
So, without even considering graphics (or ubiquitous and wireless internet access), we're looking at modern VR being at east 500x better than the tech from 20 years ago. I don't know any comparisons to make that are 500x improvements outside of tech. I don't think we can really learn anything meaningful from the VR wave of the 90s. What we have today is just a completely different situation.
VR display tech has piggybacked off phone tech, and phones are not actively looking for even higher pixel density. This means specialized research & design into display tech; something I don't see or even hear about being done.
The "2 million mirrors" in the Avegant Glyph is roughly equivalent to 1080p; about the same resolution as the Occulus and Vive. The tech is also an adaptation of the same DLP technology that's been in use in TVs and projectors for decades.
This is a printed light field - https://www.youtube.com/watch?v=6AVAzGQMxEg
This is a light field plenoptic projector - https://www.youtube.com/watch?v=blb0TUBoZwA
Exponentials are never easy but I think we're about to see huge strides in VR/AR over the next 5 years, which will be built upon the only recently established global smartphone component supply chain. There were no commodity retina OLED screens even 10 years ago.
The tech behind VR has been available for quite some time, the fact that it's still so limited (and has shown so little growth beyond the existing headsets) doesn't encourage "full surround with high resolutions in 5 years" mentalities.
It's a very different environment than when VR was build upon the desktop PC component supply chain, which brought things like the automated bank machine and interactive kiosks.