Re: A serious question.
What "The Mole" said...
Or, in other words, lacking clues as to what is content (text), what is interactive interface (buttons, toolbars, etc), and what is informative interface (window or group-box titles, etc).
In old MS Windows, menus were distinguished by being in a separate colour and place in a row along the top; toolbars and buttons looked 3-D by lighting and shading; grouped elements could have a line around them with a group name as an interruption of the line itself, and windows had a clearly distinguishable title; the rest was actual content you worked on, and was usually "flat-looking" -- like, say, text in MS Word or Notepad.
From about Windows 8, the 3-D effects were apparently declared old and un-hip, so now everything looks the same: It has become much harder to find what just tells you something, what does something, and what you can edit.
As an example, my wife uses Windows 10 with the new Web browser, Edge. When she wants to show me something or, worse, wants my help with something, I usually can't see where the browser ends and the Web page begins. I have to find my way around by trial and error, clicking on stuff to see if anything happens.