We fundamentally can’t for most of our knowledge given the complexities of the modern world. Which is why the whole “do your own research” suggestion is BS. There simply isn’t enough time in the day to become an expert in everything in order to be able to accurately judge the validity of most research. That is why stopping the spread of misinformation has value because most people do not have the expertise to identify all misinformation.

“It’s too complicated for you to understand, we will mediate truth for you” is the language of priests.