I started looking at other browsers at that point, too.
I sort of settled on Brave fairly early, even in its first general releases.
I still use FF for some stuff.
I've recently been looking at Iridium, too.
Once the favorite add-on functionality from FF hits the Chrome-based browsers, the FF decline will really be steep.
Yeah, the parts of FF I missed most was an HTML plugin I used for FR, and the bookmarks organization methods were superior. I have since tweaked my Safari & Brave to my liking.