Apple doesn’t charge developers for providing worldwide distribution across hundreds of app stores. They take 30% of paid app revenues (15% of long term subscriptions).
Apple has distributed over 300M downloads of Spotify to iOS users, since Spotify is a free app it hasn’t paid a cent for over 30 Petabytes of bandwidth costs.
I don't have too much knowledge about how the delivery of apps in iOS store works, but I could infer that it is not only hosting files. They need at least to keep multiple versions and delivery the one that fits the proper iOS version of the device. And, based on my experience with delivering desktop apps I think there is much more to that.
For example I was just delivering one single app to customers and still I needed to allocate time to infrastructure and versioning and automating some tasks and signing the code and much more.
> Apple doesn’t charge developers for providing worldwide distribution across hundreds of app stores.
Yes they do, publishing on the App Store isn't free. Also, they favor some apps they don't compete with, (Uber), while handicapping others, (Spotify). Hardly fair.