Saying this seriously a few decades after computers were room sized is I think a bit short sighted. Betting against technical progress especially in density / materials / weight is not a good bet.

I don't think that comparison works: the size of a computer wasn't a direct blocker for it being useful at all — it's great that I can use my MacBook Pro on the couch for a day or two but I could do just about everything sitting in front of a desk with a computer which was too big for my lap (or, a generation earlier, too big for the desk) because I didn't need to carry the computer around on my body.

VR is different in that the experience is worse until you reach a number of hard thresholds: the headset has to be light, yes, but you also need good display and sound quality, sensor tracking & lag has to be tight enough that you don't get nausea, input tracking has to be detailed enough to make behaviors feel realistic, etc. You also have practical problems for many applications — I can't move in VR without trashing my living room without even more hard problems unless you're doing something like making flight simulators.

That's not a hard problem but rather a collection of them and the problem is that the alternatives good enough for most people — i.e. few people are going to pay a significant premium for it, and even the people I know who have VR setups mention not using them much when the novelty wears off — and there's a real chicken-and-egg problem with needing high quality content to be worth all of that extra expense & hassle but not having sales volume to support it. I certainly wouldn't bet against it happening eventually but I think the trajectory is going to be more like “electric car” than “personal computer”.