Put it out of its misery
The extras (addons / extensions whatever you want to call them) and configurabilty are why many people use Firebox - to give them control over their web experience.
When only web extensions were allowed used, plenty of useful addons were killed (and due to lack of various low level functionality allowed in web extensions could not be ported to web extensions model)
Most of my "vital addons" do not work on "new", web extensions only, Firefox.
.. So I no longer use Firefox.
I am sure I am not alone, for security / usability many people want to have a lot of "power user" functionality in their browser - now that's not there what's the point in Firefox? Who needs another chrome clone?
.. This is someone who has used Firefox for longer than I care to remember, across various OSes! And was sad to ditch using it *
* Caveat - I do occasionally run an "old skool" version (V54 IIRC) - missing recent updates so a few security issues, but allowing "now banned" addons to run. But run it sparingly due to security implications.