But it doesn't though, not really. There are quite a few things which are still sent back as telemetry. One hell of alot better than chrome but it's still watching you. It's still not respecting your privacy.
There are some privacy respecting browser out there but they're quite inconvenient to use. I haven't found a real reasonable middle ground personally, but altering librewolf or the mulvad browser to keep you signed in has been nice enough for me
To expand:
Here's a usefull tool: https://ffprofile.com/
Firefox based privacy browser: https://mullvad.net/en/browser
To clarify why this is important, this data can be de-anonymized where anonymized and be used for fingerprinting your internet usage. If you're concerned about privacy this is a pretty big red flag, especially if your government is getting this information, which many have and will be able to in the future.
Fingerprinting isn't a perfect system and can incorrectly flag innocent people. Or, if you unfortunately life in the wrong place, whether true or not being flagged as gay/trans or the wrong political party can very much harm you. Texas has asked the government for a list of trans people inside their state, which was denied, what happens when it isn't? what happens when it's not just trans people, and is instead your group? Caution is king.