UPDATE: Feedback is, this is just point-by-point wrong. We try never to delete posts, or I would delete this one, but at the very least, file this one under, here’s a source I’ll not post from again.

Motley Fool:

One of the sources said that Apple will need to significantly improve the performance of its mobile processor technology to support a digital pen. The source also added that Apple “had to compromise on some touch performance of the latest iPhone X largely due to the less advanced chipset.”

And:

With the latest iPad Pro tablets, according to the company, when a user writes on the screen using the Apple Pencil, the screen begins to scan for input at a rate of 240Hz, or cycles per second. This is twice the peak refresh rate of the display (which is 120Hz).

And:

Apple reportedly tested a high-refresh rate display on the iPhone X (Apple calls such displays ProMotion displays) but ultimately chose not to ship the device with such a display. Instead, the iPhone X shipped with a display that could only refresh its contents at 60Hz — half that of the current iPad Pros.

In effect, the article makes the case that the current lineup of iPhones has too slow a refresh rate to support the Apple Pencil.