As for the other stuff... I've been using Firefox beta as my daily driver for a year and a half, because it's WAY FASTER than chrome, has better bookmarks handling, better built in tracker killing. The speed is only getting better as more parts of Quantum make it to beta. It sucks that it has to be so slow, but they are rebuilding an airplane while in the air with a few million passengers.
Seems like the rest of your post is just upset about the move to Webextensions. Massive API rewrites are awful. But they also bring big benefits. It is better for them to make this shift while Firefox still has some market share, so there is pressure on developers to rewrite.
All told, FF is pretty aggressively moving ahead of the pack in terms of speed and standards compliance. They already are ahead of the pack on privacy. It's not inappropriate to have marketing that pushes that excitement.
Firefox's OpenVR support on Linux is enabled in nightly, but it doesn't actually work.
You mean like https://support.mozilla.org/en-US/kb/tracking-protection-pbm?
It's crazy to see them continue to believe that firefox is great and continually improving and that losing users is due to something outside of their reach when they're piling up decisions accelerating firefox towards irrelevance.
We don't want WebVR on windows only, we want freedom of choice instead of being forced to submit to whatever mozilla unilaterally decide, we want the features that were provided by extensions that firefox decided to kill, we want an adblocker (content-blocker), we want an option to protect our privacy by killing trackers, we want a way for us users to reach developers and have our voice heard, and so on. we don't want more marketing and bs.