> And it's a pretty bad point because it only works if you constrain yourself to head-mounted (including battery) standalone devices. The article gives a nod to other ways of doing it, but otherwise ignores them for all its main arguments.

The article isn’t a complete survey of the entire field, it’s talking specifically about the most popular approaches and extrapolating what the author believes a breakthrough popularity device will look like. It does mention other options such as Apple’s rumored support devices or how industrial applications can take advantage of their environment. The challenge here is price: these systems are expensive and getting people to buy them means they either need to be cheap (impossible) or give a lot of value, and companies are assuming that means something you can easily move around in and use for long periods of time (not many people are going to set up a VR room, buy a headset and sensor array, and a pricey PC).

While it’s true that it doesn’t need to be perfect, some of the hard problems spoil the illusion - people get sick or suspension of disbelief fails - and it has to be enough better than the widespread mainstream entertainment systems to justify the much greater cost. Currently we haven’t hit the point where many people, even many self-described fans, use these systems heavily and that makes it an expensive hobby.