My worry is that the other 20% might actually come from other forms of partnerships, integrations and attempts like this, and that dropping Google might actually make them more dependent on this kind of initiatives, not less.

I don’t know how many people you actually need to maintain a browser. But if it’s actually possible to do it without any kind of money from any of those sources in a way that can be sustained, then it would make more sense to make a fork (or alternative, like Ladybird) and just use that.

Like I said, I think it’s too late for Mozilla to shift course, I don’t expect they’ll ever do that. At least not until they are forced by a competing project if it happens to become successful (or a similar huge wake up call that leaves them no alternative).