I was about to reply something similar. The Netherlands is also experiencing a loneliness epidemic, so just density and bikeability are not sufficient answers.

I was about to reply something similar. The Netherlands is also experiencing a loneliness epidemic, so just density and bikeability are not sufficient answers. For anyone that's curious about numbers on this, every western country has a long-running social survey that asks how many close friends the respondent has. This data is usually freely available.