The future is here for at least one K-12 school district that I work with. The majority of the organizations computing devices are iPad, Chromebook or Windows S. None of those devices can run Firefox.
Recentish Chromebooks can trivially run Firefox Mobile.
I actually spent last night getting a full-blown desktop FF running on my chromebook (by way of Crostini, their Linux virtualization). It's not something my mom or even my wife would ever be able to do, but it is possible. And if Mozilla really cared, they could package it in a way that would make it a whole lot easier to install.
Ah gotcha. I'm not super familiar with iOS, and was vaguely aware of such limitations but not that specific one. BTW, I didn't intend my question as disagreement; it was a sincere question.