It goes far beyond the first layer, to the ultimate layer: what is the basis of our presuppositions about knowledge? How do we authenticate what we think we know?
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.
