What’s weird to me is that Mozilla Foundation can probably sustain Firefox development from it’s investment income alone (e.g. $37.5M in 2023): https://wiki.rossmanngroup.com/wiki/File:501c3_2023_990_Mozilla_Foundation_-_Full_Filing_-_Nonprofit_Explorer_-_ProPublica.pdf
We don’t need to build Firefox though. Keeping up with the web standards and general maintenance does require a lot of work, but the base is there already.
Also, with a $100k salary, $37.5M/yr is 375 developers. If we allow EU devs where 50k€ would be a reasonable salary, that’s 690 developers now.
I understand there’s also admin work and a lot of marketing (which Firefox so desperately needs), and altogether it’s a stretch, but I believe that it is possible to pull it off.