I also use Firefox as my main daily driver and have been for 5 years or so. Recently I started trialing Arc (https://arc.net/) and it's interesting. They try to be quirky and have a bit of a different approach. What I like is that they also have the idea of different profiles (like Firefox Multi-account Containers) built in. I'm not 100% convinced of Arc yet, but it's good enough for my secondary browser (also for stuff that required Chrome, since it's based on Chromium).