Based on their 2022 report, only half of their expenses were on software development costs - around $220m, and it’s not clear what portion of that was on Firefox vs other projects.
In terms of revenue: around $100m was from sources other than Google.
Therefore, it seems plausible to me that Firefox development could still be funded with $100m of annual revenue. At a smaller level no doubt, but still in existence nonetheless.
Based on their 2022 report, only half of their expenses were on software development costs - around $220m, and it’s not clear what portion of that was on Firefox vs other projects.
https://assets.mozilla.net/annualreport/2022/mozilla-fdn-2022-fs-final-0908.pdf
In terms of revenue: around $100m was from sources other than Google.
Therefore, it seems plausible to me that Firefox development could still be funded with $100m of annual revenue. At a smaller level no doubt, but still in existence nonetheless.