A strict setting that blocked any unencrypted traffic entirely. Why the Extension is No Longer Needed
Its retirement in 2023 was considered a "mission accomplished" moment by the EFF. At its peak, the extension provided: https everywhere firefox
The primary reason for its discontinuation is that Firefox (along with Chrome and Edge) now includes an natively. Using the built-in feature is generally superior to the old extension because: A strict setting that blocked any unencrypted traffic