I don't know, those are basically the same old paradigm of separated/isolated monolithic apps. Android or iOS doesn't suddenly enable the functionality from app X to work inside of other apps unless there's a specific integration made for them.

Emacs is one environment that does it all and everything integrates with pretty much everything else simply by nature of being in Emacs. If I write a program in Emacs and it contains, for example, a function to convert a date at POINT to the correct format, this function will work everywhere else in Emacs too.