Because macroeconomy is a large subset of economy, and wereas some subset of macroeconomy are well-understood, how those subsets interact with each other and with human/group psychology, however, is way harder to understand.

But also, you can be right for the wrong reason, especially in "soft" sciences.

The article presents that economic research was causal in these wins (poverty etc). There is no justification given for that in the article, it is pure dogmatic belief.

Said another way, how do we know these macroeconomic improvements are not in-spite-of this research?

Are you calling for a debate about the nature of cause and effect, or do you have a specific observation? Do you have some evidence that completely unmanaged economies have performed similarly in those measures?

As the GP states, the article accepts the claim:

"Economists don’t understand much about the macroeconomy"

But then says that in fact economists have e.g. contributed to fewer people living in poverty. I'm simply saying I don't accept that the research of economists has improved e.g the poverty situation without some evidence of that fact.

Before the discipline of 'economist' existed human societies experienced rises and falls of poverty, inflation etc. Is that sufficient evidence for you that 'completely unmanaged' (your words, which I don't even really understand your point here -- are you claiming economists 'manage' the economy?) economies have in the past had periods of ups like ours today?

The article is bordering on claiming that economists have nfi what they are doing, but the effects of their efforts have been amazing.