I bet a sizable fraction of their mobile user base only went with Firefox for addon support.

I'd (grudgingly) move to one of the Chromium-derived alternatives that still give me uBlock and uMatrix.

It looks like there are some other tickets on the road map that have the needs:gv label (Needs Gecko View). So, it seems they are on it or at least aware of it and there is some unfinished work to bring over more of the components they have for Fennec and Desktop.