> Peak usability in my opinion. Space efficient and simple.

Disagree. Aside from nostalgia, there are numerous visual clutter issues that affect the ability to overview. Not to mention the aliased text rendering. Then you have double click to open files/dirs which might feel normal, but both younger and older people struggle with (like long press on iOS) + knowing what can be double clicked. My mom always asks me if she’s supposed to double or single click. But she can use a smartphone UI without my help.

That said, the one thing I like compared to modern designs is the very clear layering (with awful fake bevel 3d but nevertheless it does the job). This makes it very clear what toggle state a button has, and also which things are on top of other things.

I don't think it is nostalgia since I did grow up with more extroverted designs in my first OS.

I don't really see clutter here, it is as minimal is it can get. Perhaps you would disable some controls on the explorer, but aside from that everything is indeed more minimal than alternatives today.

Meanwhile my modern Windows start menu is more or less unusable. The search is decent and I might miss it. It is the only function the start menu provides for me. The modern explorer is cluttered with senseless shortcuts that tries to force certain behaviors. In this example I can probably disable the tool bar to have even more space.

Double or single clicking is supported either way. This probably provide an alternative with a context menu.

I cannot even begin to explain why the weaknesses of smartphone OS. We have a duopoly with all its negative effects and I am constantly supporting people here, far more than for Desktop PCs. That said, the use case is different.

>My mom always asks me if she’s supposed to double or single click. But she can use a smartphone UI without my help.

That's honestly just an old person thing to do, usually coupled with a huge helping of learned helplessness "I just don't get these newfangled computers" and refusing to learn anything new. Show them right click one time and they'll forever ask if you if something that they've always double-clicked on requires a right click.

double click vs single click is interesting, seems nobody knows how to handle an object needing to be interacted with more than a single way.

Maybe the right idea is to just pick one arbitrarily and stick to it consistently.

I’m only mildly joking, UX guidelines are basically just this. There is no way to make people implicitly know how to do things (skeuomorphism was a solid attempt).

In society it’s only things like hammers that have a universal/innate understood use.

Single-click was implemented possibly by 2k but definitely by XP. Think it had to do with IE—yes, details below.