I just find it really laborious to organize bookmarks properly when you get into the hundreds, and it’s more work to delete and easier to forget which in practice just means I still have decades old bookmarks I’m not interested in anymore. Tabs at least are in the way so I can remember to close them. I do use a few extensions to make it all a little easier to manage when I do deep dives into something and “need” ~50 new tabs for a little while.