I'm not dismissing their effort, on the contrary! It's commendable, but they're still way off, and would probably need years of work. A fully fledged browser is a monumental undertaking.

Mozilla.. basically they're lingering on due to Google's fear of having the only browser available and the scrutiny associated. Ideally Firefox should be funded by public funds ( like thr EU donating money to FOSS projects they use like VLC, 7 Zip, etc.). But if a browser company at it for a long time can barely survive while also having a browser that's not "fully featured"... and Microsoft, with their infinite pockets, also abandoned theirs... what hope is there for anyone succeeding at it? And make no mistake, for any browser to succeed it would need the full feature set of Chromium.