Based on that hour-long talk, I'd say Carmack just had a fundamentally different set of priorities. He seemed to be focused on latency and scale, where Meta seems to be pivoting to fidelity and graphics.
Quest 3 is supposed to have 2.5 to 3x graphics performance, so things will improve with new hardware, but you can only take it so far.
Another big problem is that things look much different/better in person, in VR, compared to a 2d video. I don't see a solution for that.
But, they do still support that type of user with AirLink/USB. Problem is, there's not enough of those users, so many of the developers target Quest users, which where the eyes are.
I think a step function in VR quality, which requires a step function in the number of eyes behind a powerful system, will come with PSVR 2.
Also the current generation of VR was basically build on top of smartphone hardware and there where quite a few ideas to make use of the full hardware instead of using it as a dumb display.
Which makes sense, you want your users to be able to really take in the graphical glory of the Metaverse.
I liked Quest2. It gave me noticeable mental fatigue/wore me out the first couple half hours I used it but it’s bothered me less since. I think the graphics qualify and UI is ‘good enough’ for the platform/tech to maintain and grow traction. But some family members found it disorienting on first try and never wanted to mess with it again. That does limit the market. And it probably is the biggest issue as you say.
I noticed three other constraints that were inhibiting success: 1) Not a lot of free fun mindless apps. The platform seems to really steer you to $30 apps as its business model. I respect that, would rather pay up front than be the product, but it limits adoption/addiction/stickiness. (Of course with Meta you might end up being both.) Never had patience to venture into the side loading world. 2) Kids under 13 are not supposed to use it. Not sure why but I believe it may have interfere with visual development (and I believe it), and I limited my kids use significantly. This limits the kid adoption/addiction/stickiness dynamic seen with, say, YouTube. 3) Creep factor. Your every move is tied to your real Facebook name. I was always conscious my every move and sight was visible to Facebook. It’s true you are tracked/with the web/internet but in a less direct way. I suspect, but don’t know that this inhibits people using it for porn, which also limits adoption/addictiveness/stickiness.
Beyond those three, two more thoughts…
As many have discussed, I’m not sure what the killer app is, but a bit to my surprise I’m not sure it is critical… There were a number of fun different unique experiences (Beat Saber, etc) so I think it may work out without one big one.
I also found that casting the screen to Chrome didn’t work a lot of the time which limited my family’s ability to enjoy it together and help each other.