I think Apple needs to come up with a better indication -- perhaps something more explicit, the first time you encounter it -- that you need to click the hardware button, not tap something on screen.

I have to agree, I did not "get" how to purchase apps to start with (one of the first things I did with my iPhone X), once I knew how to do it then it was obvious - so I would guess the physical action came first and the animation later, when everyone testing it knew how to use it.