I'm so tired of hearing about this. XUL was slow, and no one wanted Mozilla to spend millions improving a standard of which it was the sole user. There was a

I'm so tired of hearing about this. XUL was slow, and no one wanted Mozilla to spend millions improving a standard of which it was the sole user. There was a multi-year deprecation cycle. Everyone had a chance to update in advance. Sorry your workflow was broken, but sometimes the users have to pay the price for technical debt too.