There are some issues where it’s understood that people will lie. If you’re having a surprise birthday party, you might have to lie, and nobody thinks you’re a bad person for it.
Unfortunately, the scope of things we expect people to lie about is getting broader and broader. We’ve essentially given up on expecting politicians to tell the truth, and it looks like the news is next. There are also certain issues about which you can never believe anything.
Does hydroxy-whatever work? How could you know, one way or the other? People who say it works are accused of being Trump supporters, and people who hate Trump insist it doesn’t work.
Do the police disproportionately target blacks? How can you know? If you say that they don’t (as Heather MacDonald says) you get blacklisted.
Are children better off at home with mom or in daycare? Who’s willing to tell the truth and make the feminists mad?
Did Trump approve of a supporter calling Obama a monkey? Who’s to say? Some say yes, some say no.
This is, IMO, precisely why conspiracy theories grow. We all know perfectly well that there are lots of topics where people won’t tell the truth. It’s a small step from “they won’t tell the truth about [race / sex / Obama / Trump / the protests]” to “they won’t tell the truth about [Pizzagate / the “real” agenda with COVID / ….].”