This article is a mess.
The term homo economicus refers to a "characterization of man in some economic theories as a rational person who pursues wealth for his own self-interest." (Investopedia)
The author here conflates at least four different things which might possibly be considered in terms of homo economicus: individuals, corporations, countries, and governments. It is easy to see that each of these entities is capable of making decisions to maximize "self-interest" as it applies to that entity. It is easy also to see that "self-interest" for one entity may not serve the "self-interest" of any or all of the other entities.
And nothing he says addresses the headline. No further analysis is warranted.