I used Firefox for over twenty years, and after I fell in love with the workspaces feature and aesthetic of Vivaldi, I retained those, with Firefox’s containers, by using the Floorp forked version of Firefox from Japan and, more recently, the beautiful Zen browser, as well as Waterfox and LibreWolf, before finally realising I can cope just fine without containers and stick with Vivaldi, who are a larger project, while retaining a good ethos. The point is, there are many forks of Firefox to choose from if you don't want to use a Chromium-based browser.