My mental model of a browser is the same as of any tool, as a hammer, purely defined by its technical capabilities to do a job, like to display a website and offer basic functionality like for saving a bookmark.

The very idea of an entity called "we", an anonymous and ever-changing cast of people managing "responsible defaults" and "simple tools to manage your data" and communicating it on their terms, making me try and keep up, is alien to this idea. They lay their hands on our data; want to know how exactly? Follow several links to this page:

https://www.mozilla.org/en-US/privacy/firefox/#notice

The page in its tone trivializes the entire deal and is just another EULA and as such could just as well be presented in a small textbox in all-caps. It's more than the average user will ever read, and way too vague anyway.

"Be informed about what data we process about you, why and who it’s shared with (that’s this Notice!)" they say, but

...how about you show the entire dataset compiled about any user with information who is using it and for what exactly (excluding truly secret law enforcement requests). Everyone involved would be mortified with shame.