It will be as popular with enthusiasts in 2026 as the PS4 is with enthusiasts in 2016, but it will likely not take off with the Madden/CoD crowd. I think we'll be seeing some very creative experiences and/or uses of it in 2026 that have mainstream appeal (I'm expecting someone to record a film that is best experienced by someone in a VR headset), but in PC/console gaming, it's going to remain pretty niche (much as console gaming is becoming in and of itself vis-a-vis mobile gaming).
Long-term in gaming I expect it to be a peripheral that greatly enriches games, especially in certain genres, like we see with controllers and genres now. You can play racing games, flight/space combat games, and fighting games with a standard controller, but they are immensely improved by a tailored controller, and that's likely what we'll see with gaming. I don't see the bulk of games being 'built for' VR because people are cheap and hate change, but some games will be made better by its inclusion.
Speaking personally, I can say today that there are several compelling reasons for me to buy a PC VR headset (and more coming), and very few for a PS4 or even PSVR at this point in time, but that mostly comes down to genres and available libraries. I think space combat/flight sims and racing games are going to the biggest short-term beneficiaries of VR, and the strongest entrants in those fields are in the PC space right now. I don't need a VR headset for Disgaea or FF15 or whatever, and I don't expect those games to support them, because they don't need VR.
