Morality

[vulcanlogician]

I really wouldn't try to argue "atheist" are better. "Off" is a mere position. It does not denote a moral code, or a class, political view, or economic view.

The real argument to be made is that when better data comes in, you adapt that data and scrap the older bad data.

FYI Plato did not get everything right himself. Plato got the idea of questioning right, but he still did not have benefit of modern scientific method. If you read the preface to "The Greatest Show On Earth" by Richard Dawkins, in it he explains, much of humanity's chase for a utopia infected religious and political thinking with his idea of "Essence". The idea for Plato was that if you simply thought about something long enough you could find that perfect thing.  IE, "essence of rabbit" or "essence of chair". Unfortunately that idea of the perfect thing bled into religious and political thought.

I would say that humanity would do better without old mythology. I don't mean erasing history, we should not do that. But we should learn from our mistakes as a species and leave bad claims behind.

If all 7 billion humans were suddenly atheists, we would still have our differences and groups and conflicts. Our species behaviors are not in a label, but in our evolution.

Sure. I don't think I've said anything contrary to what you've said. I posited that atheists were no worse off than theists in the search for moral facts, but our nonadherence to dogma might (perhaps) work in our favor.

I don't think any modern reader of Plato considers Plato an authority. Even ancient Platonists knew better than that!

Plato was obviously wrong about a great many things. But his approach to values is pretty compelling, even if his metaphysics might have lead us down the wrong path. As you pointed out, the most valuable thing Plato taught was to question all assumptions. I don't think that Plato exempted his own ideas. My favorite thing about Plato is that he invites you to disagree with him.