This is true, but back then we didn't have the JS History API so navigating throughout a frame-based website would never update the URL in the address bar to re

This is true, but back then we didn't have the JS History API so navigating throughout a frame-based website would never update the URL in the address bar to reflect where the user is. Whether or not you see it as a big deal is up to you, but I personally have vivid memories of receiving links from users who were trying to share or show me a particular page, only to realize that they had copied the address bar's content of a framed website.