The problem isn't so much that economists don't know what they're doing. There are many questions which economists can answer quite clearly.

The problem is that economics has become the center of the entire operation of society, and is used inappropriately or where it is just irrelevant.

It should be self-evident that this is wrong; people don't care so much about being rich, as being richer than those around them. Far from being rational actors, human desires are easily manipulated. People who do not have anything to offer the market can't just 'cease trading', just as workers generally can't choose not to participate in the labor 'market'. Etc.

We need to operate society for the good of humanity, not for the benefit of 'the market' and 'profits'.