E: Hey use Firefox!
O: OK, I'll give it a try!
O: Hey, why doesn't X site work properly with Firefox?
Firefox: Introduces something making it more likely that another site doesn't work
O: Hey, now Y site doesn't work either!
E: Hey, just wait a second you can-
O: Sorry, I don't have time for this, I'm switching back to Chrome.
IMHO - Firefox's #1 priority should be making sure every site in the the first 10,000 of Alexa work equally as well with Firefox as it does with Chrome, period.
What good is amazing privacy stuff if your userbase is rapidly dwindling?
list of sites that don't work (many, if not most of these work on Chrome without issue):
https://webcompat.com/issues?page=1&per_page=50&state=open&s...