IOS has been showing its age over time as well as the problem's of being a first in an industry. Apps are supposed to be designed in a linear model (hence the lack of a proper back button) and it relies on things being hard coded and a given, which makes things weird when Apple starts adding new things to it. Google seemed to have found a majority of the problems with iOS and solved them in their own OS (including supporting any device, though they had to add new stuff to deal with tablets.) If they had to redo it, I'm sure Apple would change a lot of things (maybe. Lately it seems like their UI designers went to the same school as Samsung's.)
Why do they require you own a Mac to make an iOS app? (other than keeping you within their ecosystem)
Outside of forcing you to buy their computers and use their IDE, probably because OSX and iOS both share a kernel. You can actually see the difference when trying to run an iOS emulator versus the official Android emulator which doesn't share anything with the OS it is on (because Java.) Google even admits that you should avoid using their emulator as much as possible.
Different interface or not, if Google can make things like push notifications super simple (yet super secure), why can't Apple? Why do they require you own a Mac to make an iOS app? (other than keeping you within their ecosystem)