Some places in europe have lower population densities because of low population, not because of massive distances.
The problem in the US is that distances are way longer.
The problem in the US is that distances are way longer.
When building networks the geographical extremities of the nation do not matter, only the distance to the closest point of presence.
Europe and the US are not that dissimilar in geographical extent or population density, so neither of these can be used as convincing arguments for American exceptionalism.
The fact remains that the US is just that dysfunctional compared to Europe.