Playing a piano involves pushing down on the right keys with the right force at the right time, but that could be pre-programmed well before computers. The self-playing piano in the saloon in Westworld wasn't a huge anachronism, such things slightly overlapped with the Wild West era: https://en.wikipedia.org/wiki/Player_piano

Picking up a 1mm thick metal disk from a flat surface requires the user gives the exact time, place, and force, and I'm not even sure what considerations it needs for surface materials (e.g. slightly squishy fake skin) and/or tip shapes (e.g. fake nails).

Imagine a prosthetic 'hand' that has 5 regular fingers, rather than 4 fingers and a thumb. It would be able to play a piano just fine, but be unable to grasp anything small, like a zipper.

I'm far from a piano player, but I can definitely push piano buttons quite quickly while zipping up my jacket when it's cold and/or wet outside is really difficult.

Even more so for picking up coins from a flat surface.

For robotics, it's kind of obvious, speed is rarely an issue, so the "5x" part is almost trivial. And you can program the sequence quite easily, so that's also doable. Piano keys are big and obvious and an ergonomically designed interface meant to be relatively easy to press, ergo easy even for a prosthetic. A small coin on a flat surface is far from ergonomic.

Well, you see, while the original comment says they could play at 5x speed, it does not say it plays at that speed well or play it beautifully. Any teacher or any student who learned piano for a while will tell you that this matters a lot, especially for classical music -- being able to accurately play at an even tempo with the correct dynamics and articulation is hard and is what differentiates a beginner/intermediate player from an advanced one. In fact, one mistake many students make is playing a piece too fast when they are not ready, and teachers really want students to practice very slowly.

My point is -- being able to zip a jacket is all about those subtle actions, and could actually be harder than "just" playing piano fast.

zipping up a jacket is really hard to do, and requires very precise movements and coordination between hands.

playing mozart is much more forgiving in terms of the number of different motions you have to make in different directions, the amount of pressure to apply, and even the black keys are much bigger than large sized zipper tongues.

Thumb not opposable?