I don't use Firefox because it's Firefox, I use it because it's not Chrome.
I use FF because I want to browse the web without being signed in to everything.
Exactly: Firefox doesn't add anything I want (eg. better performance, useful features, more customizability), but it doesn't do some of the bad things Chrome does, so that's why I use it.
I had to stop using Firefox because it kept using all the memory on my machine. So I am using Edge now.
Oh, I use it as well, especially on Android where it has proper support for extensions.