We have some insight from Decision theory. Klein and Kahneman have both identified required properties for valuable expert intuition (or knowledge, tacit or not) to be available to aquire. (here's a simplified version of this by Veritasium [1])
Most people would see through the conartist claiming "I'm a roulette expert. I've done roulette for 10 years, I have 10 years of roulette expertise, you should listen to me when it comes to what number you should bet on a roulette!" Yet we all fall for other form of expert where their problem domain follow similar structures that makes expert knowledge acquisition either hard or impossible.
But every expert with a PhD want to claim their expertise to be as valid as the actual valid expertise. Combine that with internet, short form (tweet etc) communication, we tend to dumb down the conversation using "expert" to cover all the domains, to the fraud-experts advantage.
Certain fields, you should probably trust the expert almost blindly (Emergency Care, firefighters) but others, maybe not (clinical psychologist, policy maker, economists). Problem is that if we just bundle them all up, people will end up not trusting either.
"bundling up" is a recurring tactic by conartists of all kind (subprime mortgage anyone?)
If we would "rate" different field on their expertise validity (or scientific validity etc) easily understandable by layman, we might regain some institutional trust.
But that would cause a crazy amount of resistance from certain fields (macro econ, psychology, nutritional science, etc) and in real term wouldn't happen
[1] Vertiasium https://youtu.be/5eW6Eagr9XA?feature=shared