[anthonyhn]

You can disable some of firefox's background network requests by modifying the about:config key/value pairs of your firefox profile (for example, by using a user.js file). The Arkenfox user.js (https://github.com/arkenfox/user.js/) has some pretty good defaults that disable a lot of the background requests.

There are also firefox forks that disable background requests. Librewolf (https://librewolf.net/) is a popular fork that uses a combination of about:config tweaks, policies, and patches to disable all background requests (technically some requests still go through, but are replaced with a dummy url that you can block). Librewolf also downloads uBlock Origin by default, and is close to upstream. Overall it's a pretty good out-of-the-box solution.