The word "first" is doing a lot of heavy lifting here and has jackshit to do with it supporting it. Why? Because the overwhelming majority of Android users aren't using a keyboard and are using a touchscreen. You could even extrapolate the woeful state of Android tablet UX, because there's far more Android tablet users than there will be keyboard users because hey, most Android devices only ship with a touchscreen and are cellphones.

An iPad can support a keyboard too. It's a touch-first device.

A Mac can support a touchscreen with a third-party driver, but it's a KBM-first UX and support of the touchscreen is horrible in most apps that only accept one input at a time.

While I understand your point, I disagree that just because majority is using touch, you shouldn’t care about minority using keyboard.

Why? It's not an accessibility feature, and desktop OS versions of Firefox still exist. Choosing a hobbled Android device and expecting desktop-class experience is a user issue.

Will it drive worthwhile value? No.

Are there more pressing matters? Yes.

With that said, it's open source. Why don't you implement it yourself? Meanwhile the rest of us have long since moved on from Firefox.

Samsung phones can do things like wireless beam a desktop over to a TV. You can then use a bluetooth keyboard with it fine with Chrome, but not Firefox.