I don't totally disagree but multitasking doesn't have to be only user-facing apps. The notification system in Android is light-years ahead of iOS and it relies entirely on having a good multi-tasking environment. Importantly, the notifications don't have to just be from some specific set of things-that-can-notify a user as chosen by Google. Pretty much any kind of app can notify a user of anything.

In theory iOS is more than capable of supporting this on the backend, but the front end architecture is a mess and would have to be significantly reworked for even this kind of basic thing (well, it seems basic on an Android device it seems so obvious there).