This hit me the other day. iOS and the app structure is modeled after the way Apple itself is organized. (I don’t have very much inside information on how the teams at Apple are structured, but from what I know, the metaphor feels right. I’d welcome additional examples that illustrate the point further.)
Small teams working on one thing at a time with constrained resources == a single app running at a time on an “underpowered” machine with limited resources, both of them delivering an exceptional user experience in the process by stripping away unneeded cruft and focusing on making one thing at a time better. Apple being slow in releasing a new version of the Remote app because the guy who worked on it was transferred to another team in the meantime - that’s how app backgrounding works with limited resources.
iOS works, because Apple is iOS.