It's easier when you control the OS and the hardware.

But it's much harder to write your own OS in 2016, there's a reason nobody else does it.

Think about the "enhancing" crapware most vendors deploy on their Windows machines, then scale it up to the entire OS. Yeah, it would be that bad. We have to give it to Apple for still crafting their OS themselves like it was 1985, and doing a very good job at it.

Agreed. I was not criticising Apple, by the way.

It only looks easier because all the hard work went into creating a desirable combination of os-hardware that they could control.

But it's harder to control the OS and the hardware.