The article does not include the word "density" at all. Switzerland has 2.5x the population density that the US does. I absolutely believe that US regulation choices encourage telecom monopolies and suppresses service in the US, but it's impossible to make a credible argument for that without acknowledging the density challenges that the majority of the US (geographically) faces.
The average population density is pretty irrelevant here. https://commons.wikimedia.org/wiki/File:US_population_map.pn...
Lots of high density cluster and much easier geography (Switzerland famously has lots of mountains in the way).
So the question is "Why do US metropolitan areas not have 25gbit fiber for about $60/month?".