However, this kind of whataboutism illustrates my point. There's a near infinite number of places humans can congregate to enjoy each other's company. It can be a park or a coffee shop or a pub or your kitchen table for tea.
The fact that none of these are suitable demonstrates that the desire to get together is not there.
downtown Denver can house minuscule part of the population of the Denver metro area - only those affluent enough to afford it. America (again) is not downtown Denver or downtown SF or downtown anything...
My take is that Americans like to make infrastructure excuse for everything when it really boils down to priorities and preferences.
10 km is a 20 minute bike ride if you're not too obese to fit on one. 10 minutes if you pick a coffee shop, pup, or Park that is halfway. Unfortunately, most people prefer Netflix and the fridge which is even closer
e-bike ? otherwise you have to be riding race type bike with really good dedicated bike lane