That was comparing desktop OS to mobile OS

It doesn't matter. The point stands.

neither is iOS a workstation

Yes it is. It's a general computing device. The XBOX is a dedicated gaming device.

Okay but the problem isn’t the type of apps

As far as this discussion, it very much is.

So either you should be able to get application / games from multiple sources or not.

You absolutely should be able to on all platforms, but some are more important than others and comparing them like they're all the same makes no sense.