> It's rather weird to me that you need to install entire other IDE's as developer dependencies to build mobile apps, but that seems to be how it is.
I don't remember the details, but a couple years ago there was a way to install just the Xcode build tools without installing the entire IDE. I'm sure there's a similar process for the Android SDK. (Though, of course, none of that is officially supported, so you're on your own for the most part.)
Edit: Turns out Google provides downloads for just the SDK without Android Studio[1], so it looks like the separation is unofficial only for Xcode.
I don't remember the details, but a couple years ago there was a way to install just the Xcode build tools without installing the entire IDE. I'm sure there's a similar process for the Android SDK. (Though, of course, none of that is officially supported, so you're on your own for the most part.)
Edit: Turns out Google provides downloads for just the SDK without Android Studio[1], so it looks like the separation is unofficial only for Xcode.