I'm with you. I was using Netscape way back and loved Firefox from its inception, and tried to convince everyone I knew to use it. Earlier this year I finally switched to Waterfox, and I haven't looked back. I tried Librewolf first, and it was great, but they don't have an app and that was a dealbreaker for me. Waterfox feels a lot like older Firefox UI-wise, and I love the tab containers.