(Most) poor people don't trust one another to begin with. Some ethnic communities do in fact have an array of services that are provided inside the community,

(Most) poor people don't trust one another to begin with. Some ethnic communities do in fact have an array of services that are provided inside the community, like loans and food banks and so they can negotiate directly with producers in bulk. That's how these communities thrives where ever they live. In some communities, someone who wants to buy a house or a business isn't going to ask for a loan at a regular bank. Co-operatives do work but often legislators are making it extremely hard for people to organize, because of the regulatory capture that favor their wealthy allies.