It doesn't have to be churches, local school with parents association making events, libraries that have spaces for the kids to hangout with others and work on projects together, open sports areas, parks and small festivities, farmers market that have a set periodicity. But it has to have one space where people can start to meet each other so they can talk and desire more things so they can build these other spaces or have some unified way to demand it from their local mayor.
Strictly true, but if people aren't strongly compelled to show up somewhere, they aren't apt to. Historically, the "fear of God" ensured that people went to church, effectively forcing them to gather, meet each other, so on and so forth.
The only thing I see that comes close to that these days is youth sports leagues, where parents have a fear of failing their children if not heavily involved in such activities. While this does seem to establish some kind of community amongst parents of children of similar ages, it does not seem to expand out into parents with children of dissimilar ages even within the same sport, let alone an even larger community. Which is not terribly surprising as there is not much reason for someone unrelated to a participating child to show up.
I might even go as far as to say that because parents get stuck in those narrowly isolated communities, it contributes a fracturing to any larger community that might have otherwise been able to form. It is difficult to have a general community of only 20-somethings and the elderly with little in-between.
