Earlier quoted context omitted.
It's not just tabs as bookmarks. I can build up a stack of 100 tabs in a day easily.
How??? I've never understood how people can have that many tabs open and it be useful at all. At that point the information overload is too much. I have at most 10 open, and close them as I'm done with them. Helps reduce cognitive load.
Neither the back button nor bookmarks retain state sufficiently or have sufficient responsiveness to replace open tabs.