The largest country in Europe (Germany) has a population that is less than 1/3 the that of the United States, and more homogeneous than every US state (let alone all of them combined) with the possible exception of Vermont.

And I bet even within Europe you would find the best and most efficient healthcare, education and other public services come from the smaller countries. Finland and Norway likely to better than Germany and France.

Given how many of us deal with challenges of "scaling up" tech, processes and organizations as part of our jobs, I'm surprised more people don't really seem to consider the practical limitations of scale for projects of government.