That lack of capability prevents it from being my daily driver, even if the rest were good enough (I’m not saying it isn’t, I’m saying I have no reason to find out).
I am certain I have inadvertently pushed many people away from Firefox for that reason alone, because when they ask for me to add Firefox support for my tools, I have to tell them it’s impossible.
I have tried to talk to Firefox developers about that a few times, at open-source conferences and such, but they think AppleScript is some power-user feature and fail (refuse?) to understand power users drive adoption and create tools that regular users rely on.
I remember whenever a Firefox story was submitted on HN, multiple people commented “I want to use Firefox but it’s missing <whatever>”. Then Mozilla started doing a lot of questionable stuff (all of which they eventually abandoned) outside their core competency and even pulling distasteful marketing stunts, and at some point people started commenting even that. I presume many got tired and gave up on Firefox entirely. I almost have. I now root for them only conceptually, because browser diversity is good.
I also noticed that no matter how politely someone pointed out on HN “Firefox doesn’t fit for me because of <whatever>”, they always got downvoted. If valid polite criticism is buried, no wonder things stay the way they are.
https://data.firefox.com/dashboard/hardware
They're really not going to be able to dedicate resources to something as bijou as AppleScript.
They don’t need to do it themselves, they could just not stifle the efforts of third-parties who do want to and have worked on it. Multiple people started on it over the years and were simply ignored by the devs.