I think now is different. I think crowd-funding has changed the economics of such projects from a few passionate hackers working in their spare time to now being able to fund people working on such a project full-time.
There's probably tens of thousands of users willing to pledge $100 into escrow on a Kickstarter-like service, paying out when somebody to creates an open Oculus Quest firmware capable of 6 degrees of freedom using inside-out tracking.
This funding model and skillsets are suprisingly close to what's required to provide Android security updates to older phones and tablets, so there's a broader business to be built.
Many of those users are probably willing to pay a few dollars a month so such software gets continued to be developed.
My go-to response is always "put Facebook out of business".
I've been thinking about it for probably 10 years, I still have no idea what that means, but your post here got me a little stoked it could be possible
Also, FB's core business is ads sold to businesses trying to reach users doing social networking stuff...how does this even touch that revenue?
At this point, I don't think FB will ever be put out of business given how old their core user base is, knowing that older people loath tech changes.
Honestly, I feel like you could position such a project as "Deconstructing Facebook's business models one step at a time: The corporation" and hire a lot of anarcho-hacker types while positioning the company as a social-good venture. I personally would love to get paid to gradually undercut and destroy facebook.
I worry that 2 things would happen:
1. The company would become what it set out to destroy (evil)
2. Anarchist hackers are passionate but you'd have a hard time getting funding from any of the big reputable players.
Still, that would be an awesome company.