I guess it’s just a personal opinion, but I think that the 4KXX versions have much more than 720p of fine detail.
I don’t think it’s a personal opinion at all. It’s easily observable fact.
The zoomed-in image on the left has no more than 720p of detail (it’s from the Blu-ray via 720p Despecialized, resized to 4K to give a comparable size). The image on the right is 4K83 (admittedly, just grabbed the version I had handy, not the latest iteration, but it’s all the same print/scan).
The 720p has some funky contrast boosting to be certain (yay 2004 master!), but even taking that into account, it clearly has more fine image detail. I feel I need to reiterate that I’m not trying to trash 4K83. It’s the best reproduction of the theatrical experience out there, hands down. But to pretend Star Wars projection prints have that much fine image detail is silly.