Any national-scale policy will be poorly adapted for some major region of the US because it is simply too diverse geographically, culturally, historically, and economically.
It's one thing to be a Scandinavian country that has a homogenous culture and smaller population (and land mass)...and another to mix large amounts of different cultures across a giant nation of states and have everyone agree upon the same thing or be able to institute the same infrastructure.
I suspect the answer is somewhat different. Just look at their parliaments: they almost always have majority coalitions made up of multiple parties, and a diverse group of opposition parties.
What is exceptional about America is its calcification into a two party system, which I think is far more of an issue than the actual differences of opinion and culture in the American populace. In fact, polls regularly show that a majority of Americans generally agree on a number of issues, and broadly support a number of possible policies and programs. For instance, on abortion, a majority of Americans have long supported legalizing it some fashion up until recently. Through the 70's into the 90's, support even reached 60%. Only in the mid 90s did the discussion become wildly more combative and enter a stalemate.
Really, most of the extremely popular social safety net programs were created and institutionalized during the 40 years of continuous Democratic majority. What ended it, and brought about the modern Republican party and the current state of American politics, was the "Republican Revolution" in '94[0]. The 2 party system then ran into a brick wall as both parties froze into defensive turtling.
https://en.wikipedia.org/wiki/Diseconomies_of_scale
Inertia and institutional sclerosis are serious problems for organizations that are large, old, or both.
Or looking at it another way: with the assumption that a country of 30M people can have good infrastructure, and is not an outlier, and there can exists more than one of such country, what is different between 10 countries of 30M people each with good infrastructure and 1 country of 300M having bad?
Governments are big, so it's difficult to just point a finger at a specific cause of an issue, but it would seem to me the issue is not continuously building out infrastructure. That, and poorly written, but possibly well meaning, legislation that leads to regulations massively increasing administration costs on every and all areas of our infrastructure (healthcare, general construction, transport, housing).