Walking is basically free, and if you live in a walkable place trivial to build into a daily routine. Even if you exercise regularly but are otherwise sedentary you'll have improved outcomes from adding some walking. These seem to me to be obvious claims.
> just being around thousands of strangers
The nit I would pick here is that you aren't around thousands of strangers per se, but a large number of acquaintances in addition to those strangers. I see neighbors, local business owners, and the folks that work at shops and cafes nearby every time I leave my house in the city. I'm on a first name basis with many of them and we greet each other on the street. If I drove places I would miss out on the exercise and those small social interactions.
> just being around thousands of strangers
The nit I would pick here is that you aren't around thousands of strangers per se, but a large number of acquaintances in addition to those strangers. I see neighbors, local business owners, and the folks that work at shops and cafes nearby every time I leave my house in the city. I'm on a first name basis with many of them and we greet each other on the street. If I drove places I would miss out on the exercise and those small social interactions.