A lot of times I want to do something and it feels like the apps are holding me back just for the sake of being excessively simple. I've had this feeling on both Android and iOS
Or sometimes I'm on the go, with no tablet or computer and I still want to do something advanced, even if the phone screen is small.
Besides there's no reason why I shouldn't be able to hook up my phone to an external display/mouse and get a full desktop experience. (Samsung is ahead of the pack in this, but the apps are still "mobile" versions that are not as fully fledged as their desktop counterparts)