Steam alone regularly has over 10,000,000 people logged in at a time [2].
I think saying "Adults dont want a tower PC" is a pretty wide sweeping statement. I agree about Alyx. If they release a full length game that has the same level of quality that Half-life 2 had, with the same level of mod and customization support, that is going to be the tipping point. If VR is still a sub-niche in gaming/PCs, we won't see it takeoff for another 20+ years. But we may see it become the new standard.
[1]https://www.statista.com/statistics/808630/csgo-number-playe....
I don't think tethered PC-based VR is going away, simply because that setup is most flexible for development and experimental purposes, but for the mass market, I think a device like the Quest is the only thing with potential to truly take off. Especially if the weight of the headset can be reduced, as comfort remains one of the most nagging negatives of the whole experience.
Call it a tv and manage to get something to market before those have effectively gone extinct, and you have a market.
Get out of your bubble. Among non-casual gamers, tower PCs are very common.
PC VR is a dead end for anything outside of creative tools, very few adults want tower PCs in their homes anymore. When I demoed my Rift to friends they were completely blown away and the first question was "Can I use it with my MacBook?" and that was that.
When I demoed my Quest, one person sat down and ordered one straight after taking it off, he demoed it to someone at work and they ordered one, took it to a family barbecue and two of his relatives bought Quests.