Adding another comment to address this PS.:

There are many volunteers to develop features or even fix bugs, but they sorely lack management roles and work on important but niche features (unused by most volunteers) like accessibility for blind people.

Those volunteers are still volunteers inside a capitalistic system that have to get by somehow. Of course they're going to spend their extremely limited free time on the things that benefit them directly (features they need, bugs that affect them). The incentive structure is set up against them. That would be very different if they didn't have the pressure of keeping afloat in spite of their volunteer work.