This sounds like a very early adopter/developer version 1. The tech for what you describe exists, but this particular version isn't going to be it. Which I'm basing on Apple themselves, leaks says they're thinking in terms of hundreds of thousands of units in a year for this, for contrast they sold something like 220 million iPhones just last year. The question is whether they can achieve an MVP and get iterating.
>Unless other people have these glasses, they can’t see your screen either. Even if these glasses have no shortcomings whatsoever, I can’t imagine a future where everyone in the room needs compatible glasses to look at the same screen.
I can, very, very easily. But in the long interim between now and then, I can imagine remaining legacy screens which people already have for that. Because we already have them. It's not a zero-sum game, having wearable displays too doesn't somehow make existing screens shut off.
>Few people actually need enormous amounts of screen real estate
Utterly ludicrous. The only reason people use small screens is portability, size (not everyone physically has room for a large display), and cost. If there were two 12" notebooks, one of which had a conventional matching screen like now and the other at the push of a button could pop out a 30" magic solid hologram display (resizable to whatever one wanted) at zero extra mass or stored size cost for the same price, there are zero people who'd pick the former. Everything everyone does with computers and gaming and movie watching and so on benefits from full resolution arbitrary size windows. It's just that right now there is no way to separate that from the physical size of the display hardware itself.
>watching movies/playing games/reading books/doing work is niche, and wanting to do it privately is niche
:\ Come on.