You can develop a (mental) trust chain. Verify yourself that a few people seem both well-informed and unbiased, using your personal experience or research. Put

You can develop a (mental) trust chain. Verify yourself that a few people seem both well-informed and unbiased, using your personal experience or research. Put a decent amount of trust in them. When a person you trust appears to have high regard for another person's opinion, add some trust to that other person. When you notice someone says dumb or biased stuff, reduce your trust in them by a lot. Continue like that for years, mixing some independent verification here and there, and you'll have some idea of what's going on.