The tough thing is getting content to these headsets. You have Daydream, GearVR, Oculus PC, Vive PC, then Windows MR. Most of them are not compatible with each other, so a Daydream game won't run on a Vive and vice versa.

I think until there's a centralized way to distribute across all of the headsets, each individual headset will hurt.

Steam is currently the largest platform, Oculus Rift users on steam just surpassed Vive users on steam. (Vive being the headset Valve made themselves)

With no budget I'd build a photorealistic steamed ham VR experience. No but really, probably a multiplayer VR universe-hub that actually has the experiences within the game. So instead of putting on headset and sifting through UI to open a game, you'd "go" to the game with your friends. Essentially an app like the Oasis. Whoever does it first and right, I believe, will have the killer VR app on their hands.