Asklemmy

That simply is not true. Marx's sociology and anthropological work has some value but the vast majority of Marx's views on economics are no longer seen as useful, accurate or relevant. Bringing up Marx as a source us like bringing up Adam Smith, sure they wrote highly influential works but what was correct has been incorporated into the classical literature and what is incorrect, such as the labor theory of value, is taught as an example of previously held incorrect beliefs.

Very little of what Marx did is relevant to today's economics because the focus is so incredibly different.

You are finding a lot of Marxists who are educated in Marxism but not necessarily modern communist/socialist thought as sadly many of the Marxists I see are the anti-scientific types that search for proof of their conclusions.

I think you need to clarify what you mean by libertarian capitalists as their delusionary states are a sliding scale. The AnCap is even less realistic than any Marxist and much more likely to be motivated by shitty behavior (Marxists might not be correct about everything but their hearts are in a good place), whereas the neoliberal is likely confused about how the impacts of free trade can harm the local working classes and might not be as beneficial as classic economics suggests.

Krugman, Mankiew et al are often writing opinion pieces and those should be seen as such.

I don't think economics should be discussed in any format other than print as it is too hard to check the work on a video.

That's vastly less common than uneducated Marxists. The right-libertarians just tend to be idealistic and/or super racist.