When people trade their time or skills with each other locally there is mutual benefit and all the value of that trade naturally stays in the community (because it often doesn’t involve cash, and even where it does it’s off the books). Once someone spots these kind of good things (unofficial homework club, meal sharing, unofficial community kitchen etc) and tries to make it a more organised co-op so that more people can be involved, the co-op now has to register all its activities and pay taxes, which has the effect of removing some of the value from the community. If it’s an area seeing underinvestment from local government (as many poorer areas are) then there’s a great risk that’s a net-negative for the community even if the co-op is doing a “good thing”. There’s a critical mass at which the local community receives a net benefit and I wonder if many good ideas ever make it that far.

See: tax treatment of co-ops in the UK. I’m sure there are parallels in the US.