Individuals need discernment to see through the bullshit.

Plenty of "discerning" people have been taken for long rides because they thought this about themselves. This is not an attribute that you "have" or "don't have." It's a skill that you need to practice and constantly use or it will fail you, and even then, there are some seriously talented bullshitters out there.

But how do we deal with shysters like that?

Jail them? Eroding the public confidence should be a hefty crime.

Well, we use our discernment to understand that they're not trustworthy.

You ever have a class that tested this ability? Yea.. wonder why we're so bad at it in general?

but being wary of deception is not some new thing for humanity.

Yet, con men still exist and always will. We're pack animals, we're more than happy to let our guards down among each other.

How do we deal with helping those among us who have trouble with trusting people?

Effectively, you can't. "Humanity" is content to sacrifice the long term for the short term. We're prone to addiction.

giving them information and advice that might help them avoid hardship in the future.

You ever try telling someone something they don't want to hear?