I think the OP’s analysis might have made a bit of a jump from overall levels of hobbyist maintainers to what percentage of shipping code is maintained by people in their spare time.
While the experiences of OpenSSL and xz should certainly drive us find better ways of funding underlying infrastructure you do see a higher participation rates of paid maintainers where the returns are more obvious. The silicon vendors get involved in the kernel because it’s in their underlying interests to do so - and the kernel benefits as a result.
I maintain a couple of hobbyist packages on my spare time but it will never be a funded gig because comparatively fewer people use them compared to DAYJOB’s project which can make a difference to companies bottom lines.






The Oculus is too tied into being part of Meta’s data collection enterprise. I think VR will survive as a niche gamer feature and I suspect companies like Valve/Sony will be the ones iterating the designs.