Fast forward to last week and I'm considering switching back. It's not because of any sites that Firefox hasn't supported. It's because I recently needed to start using a webapp to access to email from $WORK. They locked up email and now my local Mail.app client won't connect to $WORK.
My preferred way of handling this is to wrap the webapp as a desktop shortcut, so the entire site is wrapped in it's own window, etc. I also have a couple of other work webapps that I like to treat as applications. Chrome makes this easy/possible. Firefox does not.
This used to be something I did with Firefox, but now, it's not possible (or at least easily, on a Mac). Firefox was something you could embed. And now, I have no idea.
Small little features like this are where Firefox starts to lose users. Right now I have both running, but I can't see that lasting long.
On privacy, I tentatively agree (but Mozilla's actions with Pocket etc. casts doubt), but Firefox is significantly behind Chrome when it comes to safety. Firefox's sandbox is substantially weaker (e.g. it's basically worthless on linux, because you can reach the X server from inside the "sandbox").
Not sure about Android, as I can’t remember how Chrome performs, but I regularly test things in Chrome on Desktop (or when sites are so third-party heavy, I can’t figure out a sensible way to enable sites), and on Windows the performance for both is indistinguishable, and that’s despite tons of extensions for FF and none for Chrome.
Firefox works really well on Wayland though, which addresses X's problems (and a few other regarding input and clipboard).
Edit: found out the issue you mentioned: https://bugzilla.mozilla.org/show_bug.cgi?id=1129492
That's not great indeed. I guess that the only workaround for now is Wayland