Indeed, Mozilla has a particular bad habit of not listening to customers.

It shows even in the UI design. Features like tab pinning and tab groups work in ways that are sub-optimal to how users want to use them. A pinned tab should not be tied to a specific URL. If you go their forums you see a lot complaints, and weird thing is all the nonsensical arguments that their reps advance as to how these features should work the way they currently are. I as a longtime Firefox user can immediately see what is wrong with these features as implemented, but the devs won't listen. I wonder if they use FF themselves.

Firefox is also the only app on my MacBook that consistently brings the system to a crawl. Almost every single time my machines slows down, the solution is to kill Firefox. It's got to the point I don't even need to use Activity Monitor, I just kill Firefox and and system recovers.

It's gotten to the point I'm seriously looking at alternatives, trying out Orion and Helium browsers.