I am looking for a browser which offers separate windows for separate "projects". I'd like to have one window for "general browsing", one window for "research f

I am looking for a browser which offers separate windows for separate "projects". I'd like to have one window for "general browsing", one window for "research for fitness related stuff", one window for all my open tabs for "web development research" and a few other things. Ideally it should be possible to open such windows via command line so that "browser -w fitness" opens the window with all my fitness-related tabs. I used to use the Tab Groups in Firefox but there were too slow if you use a large number of tabs.