Sounds like you might best be served by writing your own web browser, so you can be absolutely certain it won't track you.

Yeah, totally good idea. No idea why I didn't just think of that rather than hold Mozilla accountable to living up to their stated mission.

Data capture including things like telemetry or monitoring user adoption (does everyone on a specific HW config suddenly stop using the product?) is essential in being able to develop a product on a large scale that Actually Works. All of those things can be disabled in Firefox and they go to great lengths to explain what is tracked and how to disable it.

I'm pretty sure that keeping the product usable and working is part of their mission too.