Mozilla's Firefox is Floundering, in the United Kingdom Its Share Fell to 2% This Month
OUR sites are run from the UK (for the most part) and hosted from the UK. We test the sites with LibreWolf/Firefox for the most part, sometimes Falkon. The latter is Free software, but its rendering engine is more Chrome-like.
Folks may or may not know this, but in the US the more official (e.g. government) sites must ensure every user can access and use everything with a Web browser maintaining over 2% market share (it does not specify which or whose measurements of "share"). In the UK there are implicitly similar rules and the same goes for many other countries (only the thresholds vary somewhat). It's not set in stone, there's some leeway.
Given the absolute rubbish in Mozilla's pipeline (they've just appointed another nontechnical person to lead Firefox), we do not and cannot expect a turnaround. The Web is fast becoming a monoculture. HTTP is being phased out (by scaring and then obstructing users), HTTPS is becoming little but a transport layer for Chrome-like browsers, i.e. proprietary things with DRM and perhaps attestation (which means you cannot modify them; you'd get blocked for trying). █