My latest move was to merge every tab in all windows to one window only (with an extension) and start using vertical tabs (better scrolling and overview of tabs) Then sort tabs by title with another extension (Edge built in AI tab sort sucked on sorting so many tabs). With sorted tabs I could start create tab groups, Edge AI tab sort worked better when the tabs was already sorted alphabetically and managed to create most of the tab groups for me. With all this reorganization it was easier to manage all of them and to start closing tabs.
I’m not done yet but it is much better and number of opened tabs has been significantly reduced. Now I have one main window with all the tabs and some temporary windows that is only used for temporary stuff that get closed within a day.
What makes things a bit more complicated is that I also use two profiles, private and work. Firefox always sucked on multi-profile setup. Firefox’s new container stuff is somewhat improvement but not fully (at least when I tried last)