You're missing the timeline of VR. The big players, Sony, Valve, Apple, Meta, Google, all know how numerous different sectors will progress over time (optics, computer vision, display screens, chips, controls). They are simply laying the groundwork for their future brand/presence here. None of this is meant to or predated on breaking into the mainstream or even gaming mainstream. And in most cases, the cross pollination of the research means it pays off multiple times for multiple products.
A notable portion of the industry putting their strength behind some new tech is in absolutely no way indicative of inevitable success for that new tech - particularly when said new tech includes a dramatic new paradigm such as VR does.
Remember 3DTVs, and 3D in general? That had the backing of not one, not two, not three, but FOUR separate industries - Hollywood, video games, TV manufacturers, cinema chains. They pushed it for all it was worth. We had the biggest movies pushed in 3D, more than half of all screens and showings in all multiplexes switched to 3D projections, 3DTVs were pushed for all they were worth desperately for years, and Nintendo and Sony both hopped on board the 3D trend and made it integral to their flagship platforms. How did that go, exactly? At the time it could have been seen as skating to where the puck is, but no matter how much these gigantic cross industry players tried to brute force it into mainstream acceptance, they simply could not spend their way into overcoming audience apathy. You flat out cannot pay money to make people care about something they don’t care about because they perceive no value in it (either inherently, or because functionally the perceived friction associated with said thing is far more than the perceived benefits, making it a net loss to attempt to engage with it). It cannot be done.
We don’t even need to go back to 3DTVs, just look at cryptocurrency and NFTs. Look at the Metaverse! Every major tech company desperately latched on to the buzzword bandwagon, we had
car makers getting in on the far. How did that go? How is the Metaverse going?
VR in its present form presents far too much friction for any appreciable portion of the common populace to take to it in numbers that would make the current volumes of investment in that area by several of these tech firms worth it. You cannot overcome the visceral antipathy people have at the prospect of putting a headset on and shutting themselves off from the rest of the world at this present moment in time. It can’t be done.
This is neither to say that there will never be a market for VR, nor that there is zero market for it at the present. In the future, changing social trends and/or advancements in tech may well cause VR to see dramatic uptake. In the present moment there is obviously SOME market for VR - a few dozen million units of hardware sold’s worth, if nothing else. But it is a shockingly small slice of the pie being crowded by, as you yourself point out, a lot of big players. No one will come away happy from this. Facebook literally bet their entire company on it, and gave it the best shot they could. They even managed to, in very large part, insulate this push from the general negativity associated with their brand. If you want to know how that went for them, one just needs to have a look at their current share price, and also the reasons for said price.
EDIT: We don't even need to look outside of the games industry for examples of this. Look at cloud gaming! Sony, Microsoft, Google, Amazon, Nvidia, Square Enix, Capcom, Ubisoft, Bethesda, very literally every major player is pushing it, even
Nintendo has some engagement with it. And no matter what you do, you cannot overcome the apathy that is borne when the perceived friction involved with something is greater than the perceived benefits.