Given your experience, If one were to fork Firefox entirely from Mozilla, very loosely, if one were a non-profit dedicated to just the browser and not trying to build a diversified company around it, what type of funding do you think an org would need to keep up with web technology changes and build a foundational engineering team?
Mind you, our idea was to build a "browser-based OS", which meant at the time that our initial design was customize Ubuntu to the point that it could boot straight into a single-user windowless Firefox and to build all the "shell" as extensions. (I wrote a bit about on https://raphael.lullis.net/thinking-heads-are-not-in-the-clo...)
If Mozilla tried to address this, I think many Chromium-based browsers today would at least try the possibility to be Gecko-based.
This is factually incorrect, the worst kind of incorrect. Brave Browser was initially built on Graphene, which uses Gecko. They then switched to Electron because Graphene was too raw, and from there to Chromium. Also, Brave contributes basically nothing to Chromium, so why would you think they would contribute anything to Gecko?