Cue the people misinterpreting Steve Jobs’ quote that “if you need a stylus, you’ve already failed”.
The Apple Pencil isn’t a stylus in the sense that they were used pre-2007. It’s a writing and drawing tool, not a primary method of interacting with the UI. If your UI requires a stylus, then yes, “you’ve already failed”.
That said, I don’t really see the point of Pencil on a device as small as the iPhone. On the iPad, it’s fantastic for editing photos with precision and taking notes in Notepad.
Don’t try. You can’t explain it to them. Sense doesn’t work for them. ‚Steve said‘ is like the Bible to them.