What does the iPhone have to do with it?
I develop an app and use MacinCloud[1] to build the iOS version. Costs $1/hour on demand. The hardest part was getting a two-factor enabled apple id. I actually had to borrow a physical iPhone just to activate the two-factor authentication. Once it is activated, you can get away without an iPhone again.
Just saying that it is possible without the $1500 hardware. It still sucks that Apple makes one jump through all these hoops...
2) you still have to pay $100 a year to do push notifications and the effect is almost no one maintains the push severs for open source apps because the people running the actual servers aren’t allowed to.