I remember what it was like before tabs, when there was that Multi Document Interface (something like that) instead, so you had the main parent window but then each page was its own window within it that you could resize, minimise, maximise…
Like the AOL browser, come to think of it.
Tabs in Firefox were such an unfamiliar thing.
MDI was rightfully seen as a complete failure, but there was also SDI, where each open thing is a separate window. I don't know how we got from MDI in office apps being completely terrible, to MDI in browsers being the accepted norm.