With the version 130, Mozilla introduces a new navigation bar in Firefox for Android. If you don't like it, you can disable it in the "Secret Settings".
I was not a fan when it popped out on my screen. But, after sometime, it's pretty useful and saves a tap on the three dots button.
At least you can disable it.
Please show me the mozilla connect post, where at least 30 people said they want this.
How can they fuck up the UI without anyone requesting it?
I don't know. They are working on a menu redesign too:
They seem to be taking cues from iOS