You know that Firefox is Google right? Like, literally, Google is the main company paying Firefox's developers, and if they don't do what Google says, Google can just cut the funding, and they all end up unemployed, right ? Of course, to avoid a monopoly, Google would need to fund a different browser instead, but still, people have families to feed.
If you want to cut dependencies on Google, Firefox is not the answer, and neither is Tor or any other Firefox derived web-browser.