Not directly on their own usability. It was more that they broke the web, since bookmarks, shared URLs, and search engines couldn't navigate them correctly to g

Not directly on their own usability. It was more that they broke the web, since bookmarks, shared URLs, and search engines couldn't navigate them correctly to get the user back to the content that was supposed to display correctly. The static positioned content we get with CSS and JS hacks I've seen to replicate it a start but not always correct on it's own.