Earlier quoted context omitted.
There is definitely an element of nostalgia. However, a lot of earlier desktop OS GUIs do seem to be more internally consistent and with more emphasis on usability than the current crop. I think part of the issue is that things that might make sense on a phone have bled into desktop OSes, where they make a lot less sense.
I don't mean this in a dismissive way but based on your profile I'd say you're > 25. I'm curious about the perspective of someone who didn't grow up with the those os's
You’ll need an under-25 who’s both used some of these enough to really understand them, and has watched others of mixed expertise levels use them, to get a meaningful opinion. Screenshots don’t cut it, for the same reason as why modern UIs can look slick in screenshots or a demo then be frustrating in actual use.
That person’s gonna be very rare, while lots of over-25s have that experience.