A rather savvy economic-statistician once told me that economic theory is a very effective way to determine who has been able to get their theory published.
Effective at predicting outcomes of interventions. As in: My country's situation is X. If I tweak such and such policies this way, will that lead to situation Y? And then it actually happening.
Not Economic Theory, but Economic Practice as implemented by politicians and bureaucrats.
That's not to say that economic theory is all sound, but that even the soundest of theories doesn't stand a chance against the incompetence of government.