I think Mozilla and Firefox are cherished by a lot of people who would like to see them thrive.
But I think if given a choice, most of those people would prioritize the survival of a viable competitive web browser. The name of the product and the sponsor of the product are less important.
So a related question might be, "What would it take for a Firefox fork to succeed?"
If you think the CEO of Mozilla is a cancer, a fork solves that issue. Obviously, there are a lot more concerns than just the CEO. So, what else would a viable fork need?
In the end, Mozilla could implement any measures that would work for the fork, and probably do so easier. So answer the question for the fork, and you've answered the question for Mozilla.
Well a large part of the problem with a fork is that you don't see a lot of random drive by contributions. As a possible contributor myself a couple times, firefox is a development nightmare because it doesn't have a good autoconfig system that lets one download the code and start being productive quickly.
Then like chrome, i'm betting most people can't actually built it in reasonable time on their laptops since it burns a good 64 core machine with 128G of ram for a hour or two. Screw up said configuration, and your in for another rebuild loop. It can take days just to get a working development environment.
No, that is one the problems you have to solve before you can have a successful fork unless you happen to have a few million a year coming in to compete with the main branch.
I've been known to waste a weekend or two a year working on open source projects. These though generally are small things that scratch and itch for fix a bug. I don't work on projects where it takes a month+ of weekends just to get a working dev environment. I don't think that's unusual, you have to pay people to put up with that kind of pain.
A fork in no way solves this because you can't for the devs who mozilla is paying. Firefox is a huge project requiring devs with lots of experience in the technology who also like to be compensated. You can't fork firefox, you have to change the leadership or nothing else will change.
It's related to funding, but recognition is really important. Actually forking (as opposed to the GitHub fork button) is generally seen to be hostile and and will split the community (see e.g. ffmpeg vs. libav). This means that getting a fork to succeed is much harder than it would have been for the original project. For example if the Mozilla foundation went after government grants and donations for funding Firefox instead of trying to monetize the browser they'd probably have much more success than any unproven fork could ever dream for.
But I think if given a choice, most of those people would prioritize the survival of a viable competitive web browser. The name of the product and the sponsor of the product are less important.
So a related question might be, "What would it take for a Firefox fork to succeed?"
If you think the CEO of Mozilla is a cancer, a fork solves that issue. Obviously, there are a lot more concerns than just the CEO. So, what else would a viable fork need?
In the end, Mozilla could implement any measures that would work for the fork, and probably do so easier. So answer the question for the fork, and you've answered the question for Mozilla.