If those arguments are supposed to be slam dunks, then it's probably worth being pedantic about the second - standard Firefox, as downloaded from app stores, allows fewer than 2 dozen officially vetted Add-ons to be installed. [1]
It's not a great state of affairs. This is speaking as someone who's used Firefox as primary browser for many, many years.
Is there any other way of running full uBO on a phone?
Open a website in Firefox, click on three dots, click on "install", and you have an ad-free version of the app you'd otherwise find in the Play Store.
Just that one extension alone makes Firefox objectively better than Chrome or any of its Android forks. It is a slam dunk. Having all extensions available is a nice cherry on top, but no other desktop extension is as important as uBO.
It's not a great state of affairs. This is speaking as someone who's used Firefox as primary browser for many, many years.
[1] https://addons.mozilla.org/en-US/android/search/?promoted=re...