Games

I feel like glass was accidentally very beneficial for the industry.

It both drastically increased the general public's consciousness and awareness of the industry around AR/VR and then set the bar so low as to be trivial to exceed. People who mocked it know that bad AR with privacy concerns is not good, but when they try acceptable VR they are blown away by it.

It's mostly just the lack of the "killer app" equivalent that is holding us back.

tbf, google glass and similar are AR rather than VR. Honestly the technology has been improving over the last few years, though not in as dramatic a fashion as when it went from a rare lab or obscure tech hobbyist thing to something mainstream consumers could buy, if expensively, more in the same sense that things like computer gpus get a little bit more powerful each generation but stay fundamentally being the same kind of thing. The cost has also gone down a bit on the low end (though the higher end is still thousands, its possible to get a decent headset for the mid hundreds, or low hundreds if you get a refurbished or lightly used one). I dont think it will really revolutionize all that much, but I do think it will gradually become a reasonably significant area of the entertainment market, in the same way that things like video game consoles arent revolutionary technology beyond a certain segment of the entertainment market, but are still common enough to be economically and culturally relevant. With the current prices and use case, video game consoles are essentially what they are. Im personally exited to see where the tech goes, even though it probably wont be the next smartphone the way some claim.