It has bad privacy policy, lack of features and it’s boring because everyone uses it.
Maybe I didn’t make myself clear, sorry about that. I said:
that can’t be easily disabled with user.js
It is my understanding that all that data collection can be easily disabled in the settings and with a user.js 
I do apologize if I’m wrong.
What would you recommend?
- Almost nobody disable in settings
- You need to go into about:config and copypaste a file that you first need to be an advanced user
Firefox, Arc, Vivaldi, Zen , Brave and Floopa
Disagree with the being an advanced user thing. Most people start with Chrome and Edge (and I assume Safari on Mac? Not sure.) and they move to Firefox because they look it up. If you look up Firefox and are concerned with privacy, then you’ll learn about hardened Firefox. You don’t need to go to about:config to use user.js, by the way. Still, what you say is fair enough.
However, that wasn’t my question, was it? I said what data collecting that can’t be disabled with user.js. “Easily” is debatable, I’ll give you that, but there’s Betterfox that disables everything and has a step-by-step guide.
“Normal” users not only don’t care about privacy nor will they even think about it. If you’re concerned with this and willing to do something to make your web browsing private, then you can read a short guide and copypaste a file, I would hope.