you’re definitely right and it’s obvious that Mozilla can’t make Firefox as private as they advertise it because of their monetary interests (thus google is default, there are paid promotions in the home page, a lot of privacy features aren’t enabled by default).

But at least they make a decent work implementing them and because it’s free software then other projects like Tor or Librewolf can enable all the privacy features, remove the trackers and release a damn good browser.