Well essentially there are 3 browsers. Chrome / Firefox / Safari. Everything is a version of these three (besides niche browsers, like I think KDE might have their own browser)

What I mean by independent is Firefox is the only one not owned by a massive international corporation. I would say the only open source one but Chromium is technically open source.

You can for example download "ungoogled chromium" which is a Chromium fork that removes the Google telemetry

How is Apple "independent"? You're just trading one mega corporation for another.

It's not Chromium specifically, but it has basically the same issues.

They only get money from google to be the default Engine (which you can change easily)

In terms of development and the program of Firefox itself, google has no input or say…thus Firefox still being independent

I used to work for Mozilla. They are funded my many sources, of which Google is only one. Google does not drive Firefox's feature set or roadmap in any way at all.