A skeuomorph is a derivative object that retains ornamental design cues from structures that were necessary in the original. Skeuomorphs are typically used to make something new feel familiar in an effort to speed understanding and acclimation. - Wikipedia
I had to look up skeumorphic.
It’s the best UI design in the history of design IMHO. That’s what it is. Things were alive with it. Now, everything is flat and gross.