Extreme specialists are found everywhere. Mastering skateboarding at world level will eat your life too, but it's not "harder" than programming. At least, for any commonsensical interpretation of "harder".
All the rest, we do too. Except I don't record videos and I'm sure it is not childishly easy, but it will not eat my life.
Have you actually looked into CS deeply? Obviously not. (I‘m not saying this cannot also be true for music, which I don‘t know.)
Maybe you are better at CS than music and therefore perceive it as easy and the other one as hard.
It's not that uncommon for professional programmers to be pro-level musical soloists on the side, or for retired programmers to play top-level music. The reverse is far less common. I do think that says something.
> Anything as competitive as an artistic field will always result in amounts of mastery needed at the top level that are barely noticeable to outside observers.
Sure. Top-level artistic fields are well into the diminishing returns level, whereas programming is still at the level where even a lot of professional programmers are not just bad, but obviously bad in a way that even non-programmers can understand.
Even in the easiest fields, you can always find something to compete on (e.g. the existence of serious competitive rubik's cube doesn't mean solving a rubik's cube is hard). A difficult field is one where the difference between the top and the middle is obvious to an outsider.