Books are for the mentally enfeebled who can't memorize knowledge.

- Socrates

I can’t tell if this is a genuine quote or not. Can you provide a citation?

(I think something like this comes up in the Phaedrus)

Written by Plato.

Aren't books to communicate knowledge?

Wrong person you're quoting but he did not foresee the benefit of leveraging the work of others to extend and build-on-top.