[bryanrasmussen]

>Is there any reason the desktop version couldn’t do that

There is no reason any experience cannot be replicated on any computing device, barring hardware limitations.

There may however be reasons why things are easier done with one architecture than another, and there may be business reasons (not necessarily of benefit to the consumer) why a particular way of doing things will be preferred, and sometimes it will just be because the people who have been tasked with making something are comfortable making it one way and that is the way they will start because - as we are often told on sites like HN - when making something go with what you know if your purpose is to ship.