This could just be auto tested as the code would rarely change. It's like Firefox devel has a dartboard of unique and useful features to be randomly removed.

Aww man, I wonder what the reason is. Firefox is always my go to application for opening things I only use every once in a while.

Because -very- few people use it per their telemetry so they don't want to maintain it anymore. It makes sense to throw out a sizeable chunk of code that is only being used by 0.1% of your users. Lftp is great command line replacement for it and extremely scriptable.

They kinda need to stop acting like their telemetry is the full picture. Their telemetry led them to believe that compact mode was barely used, yet look at the community backlash (which they summarily ignore because "muh telemetry").