Add AppleScript support to Firefox and I’ll switch today.
I don’t like Chrome’s dominance either, but what do you want me to do if your browser does not support a feature I use everyday, multiple times a day (and that was there but was removed, back in version 3)? You’re giving me a browser that is useless for my needs, so I can’t use it.
You bet I’m thinking of leaving Chrome behind (and will likely do so once I make a clean install to Mojave, that should happen soon) but my only real alternative is Safari. I’d rather that alternative be Firefox, but it isn’t. I rely on browser AppleScript control so heavily, I’d sooner stop using a web browser than switch to Firefox.
And if you think I’m alone in that, there’s a chunk of the macOS automators community you’re not visiting. We build our tools with support for major browsers (and some minor) but never Firefox, because it can’t do it. We don’t even mention it anymore. If someone asks why our tools don’t work on Firefox, we answer that it’s because you don’t support the necessary feature. The number of people asking is lower every year.
Every time there’s a Firefox thread on HN, you see the same complaints from macOS users: poor performance, missing features (I’ve seen lackluster Keychain support also mentioned).
Give me a browser I can use, and I will.
P.S.: Even if I could code enough to add what I need, it’s not even clear to me from your bug tracker if you’d take the addition. Last I looked, I couldn’t even decipher if AppleScript support is something desirable or not.