I don't recall being sold on imminent breakthroughs. ARKit has been out about a year; ARKit 2, about six months. There are simple apps out there. But expecting original iPod/iPhone-like breakthroughs in a year is unreasonable and a misinterpretation of what was said.
iPhone X has been out a little more than a year. And if you recall, Cook touted the phone as being a view into future technologies Apple would be pursuing going forward. Such as AR.
The 3D true depth-mapping laser assisted front-facing camera on iPhone X is an outstanding example of the above and an amazing piece of miniaturized technology.
Most people think that was just about implementing FaceID. Not so. Potential AR applications will take that much farther, especially when it eventually comes to the back side of a phone. Apple investing heavily into Ax chip development is another piece of technology being necessary to realize the potential of AR. Even so-called Animoji's, while cute and fun for kids, represents another forward technological step useful in future AR.
The pieces are being developed. It does take time, even for a company the size of Apple.