The distinct ASP bump since the launch of the X says the new shiny is still selling to the punters just fine. Maybe total sales are flattening off, but there's no sign yet that Apple are having trouble generating interest in premium hardware. That day may come too, but it's been predicted as a near certainty any year now for almost a decade. Those betting against Apple staying on top of their various markets have not fared well over the last 20 years.

Yea the new shiny is still selling but I think apple acknowledges that new shiny phones sales will start to resemble the PC market they disrupted . And Apple doesn’t want to be in that position and is actively trying to disrupt the Smartphone (Apple Watch, AirPods and the HomePod ). Since Apple is a second mover I’m probably going to guess we are going to get a stand-alone mixed reality device soon. Also AirPods will get smarter and Apple watches will connect to more things .

If you compare Apple’s PE ratio to the S&P 500 and tech companies in particular, you’ll find that the market is already expecting relatively low growth.

And it has been expecting that for a long time. 5 years ago Apple's PE was below 12. Since then the stock price has tripled.

Now their PE is 18, so the market is expecting Apple to grow a lot faster in the next 5 years than it did in the last 5 years.

https://ycharts.com/companies/AAPL/pe_ratio

We'll see if the market gets it right this time or at least not as horribly wrong as in the past.

The PE ratio of the entire stock market has increased by a lot during that period: http://www.multpl.com/table

You could say that everyone has higher growth expectations, or perhaps capital is just cheaper?

Capital has not become cheaper. On the contrary, interest rates are on the way up.

But I don't think it's growth expectations that are driving stock prices either. It feels more like investors shudder at the thought of owning any of the alternatives to US blue chips.