I mean, yeah, it can make sense to duplicate information. That screenshot isn't supposed to say that all of these should be deduplicated.
But you really gotta be cautious with duplication, because it makes everything else harder to find. And I would absolutely argue that GitHub has crossed the line where they duplicate too much, across the board. It feels like design-by-committee.

This is entirely anecdotal, but what really dumbfounded me while annotating that screenshot, is that I never actually read the links in that "About" section.
I've seen this page probably a thousand times already, but I had no idea that there's an "Activity" link there, which actually seems like it could be useful. Nor a link to the README, to the CONTRIBUTING.md or for "Custom Properties" (whatever that is).
I had no idea how to report a repo until now, even though the link is apparently always on screen.

There's just so much info there, and it's presented like read-only info, not like navigation links, so I always just skipped over the lines that don't have numbers in them. I also genuinely never tried clicking any of these lines before...

Yeah? You should still make a decision. If you want it possible to watch, star and fork the repo from any of the sub-pages, then that stuff has to live in that top ribbon.

But then you shouldn't duplicate it into the Code sub-page. I'd work with split buttons, where you can look at who starred and you can add your own star, all from the same UI element. It would not even take up more space, since they do already display the count in the top ribbon as well.

Apparently this is how Codeberg does it (see e.g. this repo), so this might be where I have the idea from...