There is a big gap between the ~100M being spent on firefox per year v.s. the ~1M being spent on tor browser v.s. 0-100K that many community firefox forks are bringing in.
Even if everyone got together, pooled their resources, partook in a mass fundraising drive, I don't think that 100M is possible.
To have an independent browser, we need to move towards a world where the cost to maintain a web browser is lower, or to one where more people are willing to support that work - or both.