Apple's felt or leather served no functional purpose. They are faux realism, not skeuomorphism. Similarly, a digitally simulated voltmeter is not skeuomorphic, it is not a new object made familiar by borrowing a past form. It's just a digital replica.

Meanwhile, buttons with drop shadows, buttons that appear to depress complete with haptic feedback, are skeuomorphic. Apple Notes being yellow lined note paper could be called skeumorphic. And certainly, the rolodex tabs for letter groups in Contacts were clearly skeuomorphic.

This is an interesting video, and it initially defines the term correctly, but then incorrectly buckets many things as skeuomorphic to make a point, when in fact the objected to them tended to be they were not skeuomorphic at all.

Borrowing functional forms of the past to make new affordances comfortable and familiar, given them the right feel in your use, remains a good idea, at least for a transitional time.

Eg at 00:30, for a few seconds there's a marked difference in how the speech sounds - like the filter is turned off or something.

I think the video also mixes things up a bit. For example it compares the skeuomorphism of "Find my Friends" with that of a car maintenance training program - but the latter isn't an example of a skeuomorph ("a derivative object that retains ornamental design cues (attributes) from structures that were necessary in the original"), it merely adopts a realistic graphic design style to mirror the operation it's depicting.