Mozilla announced that the Firefox browser will drop support for sideloaded extensions in 2020.
Firefox Is Ditching Support for Sideloaded Extensions : Read more
Firefox Is Ditching Support for Sideloaded Extensions : Read more
They are likely preparing to discontinue their browser down the line, and replace it with yet another Chrome reskin, much like Opera did some year's back, and like Microsoft is doing now. That way, the people in charge can still continue to profit off of it, without having to do all that hard work of actually developing a browser. Open source forks might remain alive for a while, but with the vast majority of people using Chrome-derivatives, web developers probably won't bother testing for anything else, and extension support will be limited.Mozilla is famous lately for "giving users more control over their extensions": it means "now you won't be able to do another thing that worked well till today".