It strikes me that Plato’s philosophy derives at least in part from the recognition of how bad the consequences of civil and political unrest can be. He lived through the aftermath of the Peloponnesian War and saw first-hand what happens when tyranny and demagoguery gain the upper hand. This explains in part why he rejected the mysticism of Parmenides in favor of being able to give a clear account of shared reality. He saw for himself what happens when everyone has their own reality and words mean whatever people want them to mean. The picture wasn’t pretty.
Hermetism and Gnosticism, by contrast, were Pax Romana philosophies. They bear a superficial resemblance to Platonism, but really they are about individual, ineffable experiences of ultimate reality. As the Roman Empire falls apart, these individualistic, mystical philosophies are upstaged by Catholicism with its emphasis on the Christian Church, not the individual, as the basic unit. Hermetism and Gnosticism eventually experience a resurgence, but only under the protective umbrella of Medici mercantile wealth and a sympathetic Borgia Pope.
To put it another way, Plato did not seem to take peace for granted. Peace requires negotiation, and negotiation requires language which is able to give an account of shared reality. We don’t just stare in wide-eyed wonder at the truth; we have to be able to bring back an account. Most of Socrates’s interlocutors experience this responsibility as an imposition, as do many of the privileged today. But Plato grasped that to be freed of this burden did not lead to individual freedom any more than being freed of air resistance allowed a bird to soar. The opposite of rationality is not individual expression; it’s just violence.