I'd suspect it's likely that in countries with much larger populations, socio-cultural-economo class-like variance is probably higher, and inertia greater, so change is more difficult.
I live in Tasmania, half the adult population is functionally illiterate, and voting is compulsory, so we have a situation where the pool of talent to select from for society wide decision making is more limited, perhaps, and the decisions being made have to be somewhat tolerated by the population.
Agree in the general sense though, we should be looking to model our systems more on places like Finland and Estonia, rather than US / UK.