> Keyboards have arrow keys.  We shouldn't be talking about C-n/C-p in the
tutorial.

The tutorial states the below:

-----
You can use the arrow keys,
but it's more efficient to keep your hands in the standard position
and use the commands C-p, C-b, C-f, and C-n.
-----

So the user is free to use the arrow keys if they desire.

As for me, I trained myself to use C-f/b/p/n instead of the arrow keys
using https://github.com/magnars/hardcore-mode.el and now I almost never
reach for the arrow keys. I also found the C-f/b/p/n bindings unnatural
initially, but now they come up instinctively.