Below is what iTunes looks like on a 30-inch display. It would look the same on a 24-inch or 27-inch display (a bit less white space), but on a 4K display the abject design failure should be apparent even to iTunes engineers, or so I would hope.
Most of the content is hidden, requiring awkward scrolling and dragging to do anything useful, yet 2/3 of the screen is blank space, wasted.
Convoluted clicking and dragging is needed to do the most simple app organization between pages, and one cannot even see the destination, because it’s hidden by the screen from which one is moving the app. Also, I frequently have to try 2 or 3 times to succeed; it is the most tedious and frustrating user interfaces of any application I use, by far. I would rather edit a plain text config file than suffer through this mess.
Years ago, Apple had design sense for which I had great respect. Those days are long gone. A “design” like this shows a fundamental ignorance of usability, and I’m not even counting the convoluted kitchen sink aspects of iTunes. I see it as one more small indicator of Apple Core Rot.