A lot of users struggle with this. Mozilla needs to diversify it's revenue stream, but the options available to them are only tangentially related to Firefox. Basically, (1) the VPN service they are spinning up and (2) Pocket. I opted to pay monthly fees for the full version of Pocket. But what I really want is to pay a monthly fee to support development of Firefox core + extensions.
It's way too early to tell, but it seems like in the long run of history, they could plausibly become most well-known for creating Rust, and mostly forgotten for everything else they've done. Based on adoption trends from huge organizations and projects, we might very well see Rust (or a "Rust++" type analog) powering a lot of key software in 20 or 30 years from now, and who knows, maybe even a lot longer than that. (Maybe a lot shorter, too, but I'm just thinking about hypotheticals.)
I know it's probably not practical to monetize an open source programming language, and they don't centrally manage it, but that seems to be their big differentiator and contribution to the software world as of 2020, as far as I can tell. They were pioneering back when they were driving a lot of the evolution of browsers and web APIs, and providing a way less awful alternative to IE, but by 2020 Google's basically upstaged them in all those areas, and I don't see that trend ever reversing at this point. But Rust might live on in a big or huge way, possibly even long past their solvency as an organization.
So I don't know exactly what I'm trying to say with this post, and I don't know how it could help them financially, but maybe leaning into Rust or other similar very ambitious attempts at fundamentally shifting the software ecosystem could let them remain if not successful, at least relevant and acclaimed. Maybe Servo could've been one of those, but it seems like vaporware at this point (besides the parts Firefox cannibalized, like Stylo).
