There’s no such thing as areal maximally efficient market economy. There are always externalities, information asymmetries, insufficient regulation, too much regulation, etc and frequently all of the above to some extent at the same time.

It’s as Churchill said of Democracy, it’s the worst form of government we’ve come up with, except for all the others. Fortunately in a Democracy we have the freedoms to discuss, identify and agree solutions to these problems. These solutions will probably lead to more problems. Rinse and repeat.