I decided to try Firefox 57 (nightly) to see how many of my current add-ons would still function after Mozilla decides to destroy itself.
And it is a grand total of 2 out of 39.
Yep, that is right. Two. Just two.
Firefox is so, so fucked.
I canโt easily screenshot all of my add-ons as I have too many (donโt feel like stitching images), but those marked โLegacyโ in yellow? Yeah, those wonโt work after 57 is released.

This is almost comedic in the fail train this will end up being. I would spew more invective and expletives, but itโs pointless. This kind of incompetence takes care of itself.
Firefox will be utterly useless to me after 57 is released. What a bunch of wankers who donโt know how hard theyโre about to fail.