Because for a large number of people (including me) tabs are also bookmarks. Granted, most of them I’ll never get back to, but it’s a habit that’s difficult to break.
I think bookmarks on Desktop disappeared for a reason: They are not really useful. On Android, you can save "bookmarks" as symbol-links or install in case of PWAs. These symbols can be organized pretty good using the main Android interface. No need for a dedicated browser feature.
On Desktop, if I want to memorize a blog post etc., I use tools such as ArchiveBox, which also prevents later inaccessibility.
To memorize pages on Desktop, there're better features available that integrate more direcly on the OS level, e.g. similar to Android symbols.. There are also self hosted link organizers with tagging feature etc.
That's not sarcasm. Because this feature is missing on chrome android I only have the option to close all tabs or to manually open each tab and decide to bookmark it or not.
I disable url bar autocompletion for history, so it's only for bookmarks and open tabs, and use my bookmarks as a way to choose which sites are easy to get to.
