Often, people will defer to an "expert", who they assume knows more about a subject than they do. However, in many cases, and especially in economics, the expert thinks he knows something to be true, but it turns out that what he knows completely wrong, but he has invested his entire life building knowledge on top of bad knowledge, so he is not willing change his mind. A person who knows something that is wrong is much more dangerous than a person who knows nothing.

Then what happens is that the expert will say something, and people will accept it as truth, because after all, he is an expert. And then it goes viral. All of a sudden, everything thinks something is true, even though it is completely false.

Then entire books are written. An entire field called economics is created. Universities teach economics using these books that are based on incorrect assumptions. An entire generation of people build their knowledge on top of these false assumptions. And the cycle repeats, perpetually.

I'm convinced that the entire foundation of economic thought is wrong, and that the entire field of economics contributes negatively towards humanity.

Regarding the great depression, you can make the argument that government intervention in fact created and prolonged the great depression. You'll never really know, because you can't go back in time and run the experiment again.

If you don't understand how something works, it's probably best to leave it alone, rather than try to fix it.