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.
Strong dislike, I like my bars at the top, not the bottom. Looks like it's disableable for now, but will it always be?