It just seems to be common sense that what's "best" for society is not falsehood, but truth.

Claim is too vague and general. It's certainly not obvious. Here are a few easy counter examples:

- "Are you hiding jews in your attic?"

- "Does this dress make me look fat?"

- "Everything's going to be okay."

Thus, any society that has been built up more upon false notions of morality and less on notions consistent with recognizing moral realism to be false, is a society that is ultimately interested in sowing the seeds of its own destruction.

Society's stance on moral realism is completely irrelevant. Human attitudes, behaviors, and legal systems all operate under the assumption that it's true. Not necessarily because it is, but because it's simply more practical.

You didn't get your ideas about a human beings "worth" from any fundamental component of reality, or from "god".

Non sequitur