While I agree with you about Plato, I think you are underestimating our other sources on Socrates. The historian Xenephon was also one of his students and talke

While I agree with you about Plato, I think you are underestimating our other sources on Socrates. The historian Xenephon was also one of his students and talked about him in his works, including Socrates' trial and death. The playwright Aristophanes also parodied Socrates in one of his works and while it is a parody what it is parodying is consistent with what we know of Socrates' philosophy as presented by Plato and shows he was a fairly well known figure at least among the play going audience.