Well, they did. iPads are now replacing POS registers and kiosks. Although a part of me dies when I see iPad Pros being used for this, because it’s so powerful and capable yet being used as a big touch monitor.
One of the main drawcards of using an iPad or other tablet for a POS kiosk is that they're significantly cheaper than an actual designed for purpose touch screen. Those big bulky touch screens are incredibly expensive, especially for what they are, they can cost up to $2000 and still only come with an i3 and 8 GB of RAM.
The big iPad Pro made a difference here too. The older iPads so t get enough music on the screen.
What? Annotating scores is a main use for me. I do it constantly. It's something the ipad is great at.
Compared to typical Windows laptop trackpads or most Android phones’ janky scrolling, Apple does a much better job getting better performance out of their hardware.