While I'd begrudgingly agree the two are not independent. I moved back to Firefox from Chrome exactly because Firefox became once again performance competitive thanks to Quantum. Most (all?) the big Firefox improvements were integrations of Rust code pioneered in servo. The only chance I see for Firefox is doubling down on that and replacing more and more components with those Rust rewrites. If not for that I don't see Firefox remaining competitive with Chrome for long.
> The only chance I see for Firefox is doubling down on that and replacing more and more components with those Rust rewrites
If Firefox has no more Rust developers now, it can't "double down" on replacing components, and all software is prone to bitrot, so after a few years, it will be an unmaintainable, buggy mess.
I think there is confusion here over the meaning of "Rust developer".
Mozilla did lay off most of its employees that were working directly on the Rust language and its implementation. This was a handful of people.
Mozilla also laid off some employees that were using Rust, such as the Servo team.
But Mozilla still has plenty of employees that know and use Rust, both in Firefox (e.g. the WebRender team), and in code relating to Firefox such as services. This is a much larger number of people.
I'd like to see Mozilla focus on Firefox, so that there it remains a viable alternative to Blink-based browsers for as long as possible. I think that may yet become really important as the effects of the incredible dominance of Google in the WWW become more apparent.
I'd also like to see the Rust ecosystem prosper, but I guess others can take up the slack, it is gaining considerable momentum and quite a few places are looking into it, or using it already. If that isn't possible, is there much hope for it anyway?