My worry is that the other 20% might actually come from other forms of partnerships and integrations not unlike what they probably had in mind with this, and that dropping Google might actually make them more dependent on seeking 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).