I don’t understand how Apple is getting away with charging other app stores. At most they could charge for hosting the either app store’s app on their store, but that should be it. They have no other costs that they can justify since they aren’t hosting, vetting, or curating the other store.
I’m a vim user and I would say it’s not. It’s very powerful, but only once you become familiar with the commands.
Nano is a better default for the average user because it works in a way most users would expect for a text editor to work.