[czottmann]

I have. (Web dev here.) I know it works but I don't want to set up all the things just to get some basic scripting capability.

My point is that there is zero local API surface for interacting with the application. That's the reason why tools like Keyboard Maestro support Chromium-based browsers but not Firefox. Which, in return, doesn't help Firefox's popularity, because it's nigh impossible to work with it from other apps.

Disclaimer: I am in a weird spot here, for I am serious about automation both as a consumer and as a software maker -- I write macOS automation tools myself, e.g. https://actions.work/browser-actions