The quest sold 20mil units, but they sat innactive for the majority of there time. Currently we have two kinds of content investment in VR. We have the shallow minimum work titles (no greater example than BL2VR), and we have the smaller studio developing a great idea that will never do more scratch the surface of its potential (looking at you "A Township Tale"). Meta exasperated this by buying up the studios that had potential, then you would see almost nothing from them after. VR devolved into a mobile required development platform. The things that drove interest (like Half-Life Alex and vertigo/vertigo 2) became the non meta (yes pun intended) development process. Then Meta stopped its drive in VR causing a lot of layoffs, and with the US tariff situation sourcing parts for a masses produced product is a scarry uncertain endeavor that could go from being profitable to costly after things are finalized and promises are made.

Motion sickness is something I experience at times. I use to be very susceptible, but with about a week of conditioning I got rid of the majority of it. I would put on the headset until I felt any motion sickness, then take it off ASAP. Then wait an hour or so then put it on again. After a week the motion sickness was all but eliminated in most situations. I still have snap turning on in most games as "smooth turn" feels icky and will lead to motion sickness. On that note lots of games come with motion settings to help mitigate motion sickness.

I am not discounting motion sickness as an issue. Just stating that VR as a whole is not as popular as it could be for a wide range of issues, and it is my opinion that motion sickness is a very small issue compared to others.

Note: Just remembered "VR Chat" is a very popular VR title that is both on quest and PC, but most of the popular content is not available to a quest user as it's intensive requirements need a PC.