As far as the browser should be concerned, yes it is trusted. It's up to another layer of security to help the user not install extensions (or any other softwa

As far as the browser should be concerned, yes it is trusted. It's up to another layer of security to help the user not install extensions (or any other software) that they do not want on their machine. This security is a farce anyway. Firefox is installed in the user profile so any sufficiently advanced malware can just patch the firefox binary and embed itself in there or disable this nonsense. The extension shenanigans is just done to take away user control, with the excuse being to protect users from malware.