They get roughly $0.5B in easy money each year from search partnerships. I call it easy money because all that is asked is to
keep Google the default search engine. You could argue that they do need to deliver
something for this money, in particular maintaining a decent market share so that the search deal makes sense.
Not really. Market share has been in a 12 year(!) non-stop decline:
https://gs.statcounter.com/browser-market-share#monthly-2009...
And yet the value of the search partnerships seems relatively stable. Probably because Google wants to avoid regulatory pressure. Google could destroy Mozilla today, but won't. $0.5B is pocket change for Google in comparison to the $20B they wire to Apple for being the default search engine.
Still, getting $0.5B whilst failing and being shielded from market forces that other companies face is a luxury position. Mozilla would be long out of business if it was an actual business. There's also very few NGO-type of organizations with this type of generous funding.
Can this $0.5B be used to recover market share for Firefox? No. It's not an engineering problem. Safari wins because it has no competition on iOS. Chrome wins because it's shipped as a default on Android and Google uses platforms with billions of users to push it (Youtube, Gmail, etc). Mozilla does not have this "browser push" capability. And even if they would have that, they're unlikely to out-engineer the giants. Having your own browser engine is not a competitive advantage, as Microsoft learned.
Hence, Firefox is in a "keeping the lights on" mode whilst Mozilla tries to invest in other things. Such as upping the pay of failing executives, writing activist blogs, puzzling acquisitions that don't make any money (Pocket?), and they're even cocky enough to give away money in the form of grants.
They're used to easy and free money. To be able to constantly fail without much consequence. To be able to work on things with no impact.
I do want to end on a more constructive note. The way I see it, the world lacks a model for funding our digital common goods. W3C, ICANN, Mozilla (Firefox, MDN, the like) but also regulatory bodies (i.e. privacy) can be considered shared infrastructure. In the bigger picture they cost pennies to fund so it's quite pathetic that as a world we can't even organize that.