Hard to pick a 'worst offender', the System Settings panel in Ventura may be a good example, it is a literal struggle every single time I need to change something, typically as a result of some setting mysteriously changing itself back to what I do not want.
I haven’t yet installed Ventura. I had to downgrade from Monterey because the cmd-L keyboard shortcut had stopped working on Contacs.app
Therefore, the problem of GUI design becomes one of navigating the complexity/depth-of-knowledge curve, as much as it does creating a usable set of features at each point along it.
The most egregious offenders are the latest Windows, 10 and later, IMHO. When I was a kid, (coming from the world of RISC OS which had a much shallower GUI) trying to understand the big deep Windows interface, I joined the dots by telling myself "This is how they put it together. This is how they are trying to make the things work consistently and in concert." I rarely broke out of that story-telling loop.
Now, when using Windows 10 or later, and a few clicks brings one to a Windows 2000 and before-era network dialogue box, the "fourth wall" as it were, of GUI design is broken, the story-telling loop above is replaced by a jarring feeling of bewilderment or all-too familiar frustration, and it's obvious they are shipping the org chart, and doing so over time, as much older GUI components are still available.
At the risk of sounding nihilistic, I fear that both OS X and Windows have reached their respective local maximas of design, and we won't see any changes for the better (by the above metric) any time soon.
Operating systems should be modular, allowing the user to reduce as much bloating complexity as possible and needed.
I do not need unstoppable “gamed” and “studentd” services on my computer. The sealed system implemented by Apple has actually meant the overthrow of the root user by the corporation. Now I can’t reduce complexity, bloatware.
The only solution seems to be praying that BSD or Linux become useable one day
Yup, updated my comment to clarify that point -- thank you. "the overthrow of the root user by the corporation" -- damn. Good turn of phrase :-(
Modular systems have more possibilities, which means some of those possibilities might not work, and then you might find yourself unable to use an app without reconfiguring in a way that breaks some other app.
They are great for tinkerers and specialized applications, but for people who want things to Just Work, every time, no matter what, even at the cost of zero hacker friendliness, Android's model seems to completely blow Linux away.
We should still have root(I think lack of that might be part of why Android hasn't started taking over other markets), but there should be obvious and standard ways to do common things.
I don't think it's clear that those reasons have much to do with any property of the OSes though.
The rest of the OS would be a nightmare today for so many reasons; but the UI was fantastic.
The only thing I didn't like about MacOS was occasional system lock-up and application crashes due to real multi-threading. Back then, when your Mac crashed, it crashed hard... like your cursor didn't move. ;-)
And the window management as a whole seems like a case of form over function, with no way to see what windows are actually open, or switch between several of the same application, without multi-step processes (Expose/MC or cmd-tab cycling)
On other hand a menu bar at the corner of the screen has an infinite size if you are using a mouse, a trackball or a touchpad. But it's size is finite if you are using a touch display. Let me explain what I mean with infinite size. You can overshoot arbitrarily far when using the mouse and you would still be inside the menu, since top of the menu is the screen corner.
While writing this, I've noticed that in a maximized Firefox under Gnome this isn't true anymore. There is at list one line of pixels above menu. When you click on them nothing happens. Therefore I cannot overshoot anymore. Another failure of modern UIs.
IMHO UI usability hasn't been Apple's strong suit for a long time. In fact, as someone who has to use both Mac and PC, MacOS is just as terrible in many ways in not worse.
What they do well device integration usability across their ecosystem.