There is "only one Firefox" but Firefox exists in a market that is not just commoditized, but subsidized to the tune of billions by 3 of the 10 largest companies in the world.
The world may need Firefox but it's funny how people complain about Mozilla's dependence on Google while also complaining about every attempt to become more financially independent from Google.
They could start getting some of that goodwill back by not paying their CEO a multi-million dollar salary and opening donations to actually help fund Firefox.