And actually it is better for innovation not to use to Blink. WebRender is potentially much more performant than any other engine and it would never had existed if Mozilla were just aligning with Blink
It's not like the other Blink or Chrome based browsers are doing great, sure Brave and Vivaldi is getting some press, but they have even less users than Firefox.
Sadly Firefox isn't peoples mind anymore when they think browser. It's IE all over again, but with Chrome, Only Chrome is moving forward. I don't know if there's anything Firefox can do, other than marketing. It's currently the best browser out there, but that was the case when IE6 dominated the web as well.
Firefox doesn't need to dominate, but hitting some like 20% market share would be fantastic.
This isn't directly relevant in the larger context of this thread, but Firefox's sharp drop—even after the introduction of Quantum, which I've found to be a big improvement—is what makes their situation much more scary to me.