Apple's hardware aesthetic design feels outdated 
But that's the curse of the trendsetters:

This happened to Rolex before.

Most watch brands has a very specific look. It's quite easy to spot a Patek Philippe, Richard Mille, Cartier from 10 yards away.

This is not the case with Rolex. 
- Submariner looks like your average dive watch 
- Daytona looks like your average chronograph watch
- GMT-Master II looks likes your average GMT watch

The reason is that Rolex pioneered those categories. So of course all dive watches look like the submariner...

Apple's designs were a major contributor to the aesthetics of today across UIs, Hardware or, even things like packaging and physical stores.

But now that their aesthetic is so well adopted, it feels outdated and generic for their own products and we just unreasonably expect them to usher in a new aesthetic for the next generation, without breaking faith with hundreds of millions of users.