Ancient Greek philosophers' views on slavery are complex and can't be boiled down to a reply that would retain all the nuance yet would not be annoyingly long to read. Nonetheless, their views on slavery do not invalidate their views on politics.
Are you unable to grasp that someone can explain an opinion without holding said opinion? Are you unable to grasp that I can describe a political system without advocating for it? That I can show the history behind it without endorsing it?
Are you unable to grasp that you can agree with someone on one topic without agreeing with them on everything? Are you unable to grasp that people are more than one-dimensional points on a spectrum and that there can be nuance and intricacies in their way of thinking, some of which is agreeable, some of which is not? That no idea or person can be described merely as a binary choice of "good" or "bad"?
Or have you no grasp at all of the rules of logic and the art of rhetoric, leaving you with nothing but strawmen and ad hominem left?
You're not "explaining" anything, clown, you're making a vague reference to a classical work.
You're also calling the people too stupid to govern themselves and hoping no one else has read enough of the two most famous and most read philosophers in the world to call you on your bullshit.
Go cry into your unpainted marble statue pfp about it happening anyways.
For his time, Socrates (whether actually real or Plato's fictional character for the dialogues) was incredibly, dare I say radically, forward-thinking in his ethics.