Earlier quoted context omitted.
Agreed about discoverability issues. Everything is hidden. Hiding power user features is one thing, but you can't hide the basic stuff. 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.
Yeah. I first started using MacOS seriously for a job a few years ago, and I was amazed at how poor the discoverability was, especially given its reputation. Important functions were hidden behind arcane modifier combinations or only available via "intuitive" gestures that you'd never work out on your own. I don't think this was just a case of unfamiliarity - as a usually-Linux user I've been unfamiliar with Windows…
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.