Mozilla's commies are trying to kill Librefox which would be similar to Ungoogled Chrome, removing all the third party big tech spying crap.
I'd recommend an older version of either Firefox or Waterfox, with some basic privacy add-ons installed, like Noscript Security Suite, uMatrix, HTTPS Everywhere, and a browser agent spoofer.
Go to about:config in the web browser and disable webGL and webRTC. Remove any urls as well, including Mozilla urls. Make sure telemetry is completely disabled, as well as anything suspicious, look it up and decide whether or not you need to disable it. There are plenty of online guides showing how to work around about:config and its an essential tool to learn if you want to rid of default spyware/bloatware that came with your web browser.
Some will claim the older it is the more insecure. Thats a crock of shit, don't listen to that nonsense.