Is there a general trend of losing web users to mobile? That might explain the slow decline.
Firefox do have ublock origin but is lacking other extensions.
I'm using chromium-based kiwi browser, fast as chrome, with full support for extensions
So I moved to a chromium based browser.
I was using firefox on my laptop because it was in synch with my phone, but bit by bit I started using it less and less.
At firefox they are not paying attention to users, so they are losing them slowly...
This definitely seems like a decent explanation in my opinion. Sure Firefox is available on mobile, but on iPhone there's not much point to it since its WebKit anyways, and Androids have Chrome on them by default, which most people are already comfortable with.
I feel like I care more about my browsing experience on my desktop than I do on my phone, and I would guess that's a fairly popular opinion, so on mobile I usually use the default, but on desktop use Firefox.