, DeathBy​VisualStudio wrote

@AndyC:

Let's just call it a big phone shall we?

What you're missing is that if you were designing an OS from scratch today with absolutely no legacy cruft whatsoever, even if you went with a "desktop" style paradigm with overlapping windows etc, you still wouldn't design it in a way that requires users to "open" or "close" applications. It's a throwback concept to a more simplistic design age. It just doesn't make sense to burden the user with that kind of manual resource management when the OS is far more capable at doing it - that way you let the user focus more time on the thing they are actually trying to accomplish.