Earlier quoted context omitted.
Music notation is actually terrible, even musicians agree to that. It clearly developed as a way to reason about music that already existed in the west at that point, rather than be a principled way to go about understanding the underpinnings of music.
Maybe it is, maybe it isn't. But it's not keeping people from being musicans. Im 57, and have been playing the piano for 50 years. (I still practice 2 hours/day). The problem with piano isn't reading the music, it's getting your hands in the right place, at the right time, with the least amount of effort, to be able to control the keys the way you want to. Most of my practicing is getting from one place to another on…
I humbly submit that this is the perspective of someone who learned to read music 50 years ago and at an early age, and so who has, for most practical purposes, never not known how to read music.
That perspective will not necessarily be shared by a beginner who has been learning to read music for a few weeks. Sure, you can learn what the lines mean in each clef, and then you can learn to recognise lines above and below the standard five, and then with time you even learn to recognise lines far above and below. You can learn which lines mean something different by default if you have sharps or flats in your key signature, and eventually you actually remember that natural sign just after the start of the current bar before you incorrectly play B-flat for the middle line of a treble clef because your key signature says so. Oh, and you're playing the piano, so you also have to do all of this for a major chord. And a minor chord. And chords with added sevenths. And chords with suspended seconds or fourths instead of thirds. And inversions that almost look like chords with suspended something but that actually have four notes at odd spacing. And then a further note on the octave to make sure all five digits get a workout. With a random double-flat in the middle. Which lasts a strange amount of time, because you're playing that chord as part of a quintuplet. With markings showing suggested dynamics over the whole phrase.
I doubt anyone learns to read all of that fluently in a week, or a month, or even a year unless they are playing far more than any normal beginner. Yes, you can learn the main lines on a stave in a week, but the other 99% of reading music also takes years for most students.
This isn't to say that getting your hand to the right position efficiently and then playing with the action you want doesn't matter; of course it does. I'm just arguing that reading "the right position" from realistic, non-beginner scores is itself a significant challenge for most players, often for many years.