Socrates had this to say about literacy:

> In fact, [writing] will introduce forgetfulness into the soul of those who learn it: they will not practice using their memory because they will put their trust in writing, which is external and depends on signs that belong to others, instead of trying to remember from the inside, completely on their own.

Presumably very few people since Socrates would argue that society would be better off without writing. But it's a legitimate point. There is a cost to any new skill or technology. We should be conscious of what we're giving up in this exchange.

Socrates never argued that society would be better off without writing! Writing had existed for three thousand years by the point Socrates was alive, and the Epic cycle of Homeric poetry had existed for about three centuries.

In the very same dialogue where the excerpt you quote comes from he also said:

"Any one may see that there is no disgrace in the mere fact of writing."

And the section of the dialogue your quote comes from is preceded by this suggestion:

"Shall we discuss the rules of writing and speech as we were proposing?"

and later right before the bit you quote from:

"But there is something yet to be said of propriety and impropriety of writing."

So they are not discussing the merits of writing per se but the ethics of writing.

This excerpt you offer comes from a stretch where Socrates is telling a story. This is merely what one of the characters in the story tells the other.

Further in the dialogue Socrates clarifies:

"SOCRATES: Well, then, those who think they can leave written instructions for an art, as well as those who accept them, thinking that writing can yield results that are clear or certain, must be quite naive and truly ignorant of [Thamos’] prophetic judgment: otherwise, how could they possibly think that words that have been written down can do more than remind those who already know what the writing is about?"

and the rest of the dialogue is also quite illuminating:

"PHAEDRUS: Quite right.

SOCRATES: You know, Phaedrus, writing shares a strange feature with painting. The offsprings of painting stand there as if they are alive, but if anyone asks them anything, they remain most solemnly silent. The same is true of written words. You’d think they were speaking as if they had some understanding, but if you question anything that has been said because you want to learn more, it continues to signify just that very same thing forever. When it has once been written down, every discourse roams about everywhere, reaching indiscriminately those with understanding no less than those who have no business with it, and it doesn’t know to whom it should speak and to whom it should not. And when it is faulted and attacked unfairly, it always needs its father’s support; alone, it can neither defend itself nor come to its own support.

PHAEDRUS: You are absolutely right about that, too.

SOCRATES: Now tell me, can we discern another kind of discourse, a legitimate brother of this one? Can we say how it comes about, and how it is by nature better and more capable?

PHAEDRUS: Which one is that? How do you think it comes about?

SOCRATES: It is a discourse that is written down, with knowledge, in the soul of the listener; it can defend itself, and it knows for whom it should speak and for whom it should remain silent."

But I think everyone since Socrates would agree that it's a good thing someone else wrote down a bunch of the stuff he said.