Interesting ideas, but I have never liked this dichotomy insofar as it suggests an 'us against them' mentality. Like, we are one way and you are another, so we lack common ground for rational discussion? No, that won't do! Not that I think that is what you are saying.
Actual communities are sui generis: each is unique. Different levels of social connection or cohesion may exist across many different areas of economic and social activity, forming many complex, interconnected networks that have a real history that played out on the world stage.
Any particular connection or set of connections can be criticized on many grounds, but how ‘individualistic’ or ‘collectivist’ may not be very helpful. Indeed, you evaluate these two based on happiness levels, which is an indicator, but the dichotomy is too simplistic to support one over the other. Even if one could be said to be inherently better at producing happiness (which is unlikely), trying to impose that inorganically on another society is a recipe for disaster (as we see in American foreign policy!). These things must (and ultimately will) develop organically, with or without interference.
Community is important. It is important to have solid social networks. But communities cannot legitimately request major sacrifices from their members, and even the pressure to do so can be seen as despotic. We exist as individuals, and a community that fails to recognize this cannot persist.
But as I said, this is all very complicated, with so many dimensions. You mention individualism/collectivism as one of six dimensions, but there are many dimensions/variables within each.
Think about the importance of history and culture, and the role that these play in supporting or precluding one or the other, temporarily or for good, or in forming some particular hybrid.
And technology! Cryptocurrency offers a future with decentralized institutions — a libertarian (and thus individualist) wet dream. But at the same time, bitcoin (etc.) is a network of many people around the world: it is a collective, a community, and it is this collectivity that has sparked this libertarian revolution. Our large, centralized institutions have separated us into individuals, with narrow, limited communities. The freedom and openness offered by decentralization offers great promise for the building of new social networks — new collectives.
In any case, I think the dichotomy is useful and I enjoyed your article, but it would be better if you followed up on your comment below, regarding potential ‘optimal combinations’.
Thank you for the thoughtful comment, @theperipatetic, I'm glad you enjoyed the article!
I completely agree with you on dichotomy - as I mentioned, think that none of the extremes is good and that the point is to find an optimum between them.
I also agree that when one nation aggressively imposes its cultural norms on other nation(s) it usually ends up bad.
It is indeed impossible to link individualism/collectivism with happiness in general, but the comment above made by @vieira and my reply to it may interest you. : )