A community is about people.
People perform many functions than just the one at hand.
Some years ago I consciously continued to go to the full service station near our house, paying a slightly higher price for gas. The person who pumped the gas was another pair of eyes and ears in the community. Whether he fully realized or not he scanned the sidewalk and street while he did his duties and if a senior was in distress or a lost child appeared he could do something. He also kept a wary eye out for the odd drunk that hung around the nearby liquour store. He provided an external benefit to the community.