Having shared assets to maintain is legitimate, but the vast majority of HOAs (those governing single-family neighborhoods) don’t really have that as an excuse. Even if they do have something to maintain, like a private street or a pool, it’s only because the local government was shirking its responsibility to provide what should have been public infrastructure.

(And that’s why they’re so common: because low-density development is so ruinously unsustainable, governments heavily encourage developers to establish HOAs so that the time bomb of future maintenance is the homeowners’ problem instead of bankrupting the city.)