I'm in a similar type of place (Boston surburb) with extremely high mask adherence outdoors when walking by. But studies show that walking briefly by people outdoors isn't actually how you get it in the vast vast majority of cases. So it's a little bit of covid theatre.

I've been wondering the same thing as you. In general I tend to believe the adage of you don't get covid from strangers, you get it from people you know explains some of it[0]

Also the people you see on the street are probably (at least somewhat) responsible adults and not college students packing into football mash pits [1]

[0] https://www.dailynews.com/2020/05/15/coronavirus-who-gave-yo... [1] https://twitter.com/ematthemoment/status/1325299966961659911