Wacom also sells drawing tablets with integrated displays [1]. I've never used them or an Apple Pencil, so I don't know how they compare, but Wacom isn't totally caught out here.

On the other hand, I can see a lot of people buying (or already owning) iPad Pros and using this feature who might not buy a dedicated device for it.

[1] https://www.wacom.com/en-us/products/pen-displays