If you look at the population densities of median American and European cities, they're quite similar (~13,000/sq mi. or 5000/sq km.). Which makes me wonder why you insist on comparing two cities that are not remotely comparable. Seems like cherry picking.
> ED: I should add that I don't consider New York an average American city because it's a success!
I'm almost curious why you consider the "average" U.S. city "not a success", but this remark smells too much of the pompous anti-American groupthink that has become so popular on HN lately, so I know better than to expect a rational explanation.
Honestly, I'm starting to find your undeservedly superior attitude and cherry-picked data tiresome, so I don't think I'll bother with this conversation anymore. Have a nice night.
ED: I should add that I don't consider New York an average American city because it's a success!
[0] (Wikipedia, but calculated from https://www.insee.fr/fr/recherche?idprec=3293086&q=paris&deb...)
[1] https://en.wikipedia.org/wiki/List_of_United_States_cities_b...