It’s likely mostly Google and a bit of Amazon: Casting support requires Google Play Services installed on the device. Google Play Services is only allowed to be used (as in: allowed by Google) if the Android device also comes with many other Google apps. Amazon probably doesn’t want their device to become a Google-centric device. That’s likely the reason.

If I recall correctly, it was meant as a measure against fingerprinting. It’s basically one less thing to uniquely define a user based on the info that the browser gives to a website. I’m not sure if it’s still like that, cause it’s been easily a year since I used LibreWolf.

I applaud LibreWolf’s efforts, but the hard-coded timezone makes it unusable for me. Other than that, it’s a great browser. I used it several months until the timezone confusion got the best of me.