I think it may also be that initially, skeumorphism was used to educated the general public as to the intuitions of the UI, but after that intuition become more and more widespread generally, the UI could turn into a more abstract and minimal form of the previously skeumorphic UI while retaining its properties / placements etc. This abstraction then allows interaction paradigms that cross-cut what is possible physically, or to add more to the now-abstract UI with less noise. Technology is changing of course, but also humans are changing collectively in learning to communicate with it. This is also historically present: at some point typing wasn't a thing, then some jobs did typing, and now typing is a widespread skill and allows interactions at a new level once that is established as assumed on the part of the user.

>Guess it has something to do with the change in software UI language.

In the sense that software UI follows our societies general trends. And as always in design trends, there's a feedback loop.