Your understanding of poor is really different from mine. Here (Europe) poor people don't buy online, they go to the store for food, it's cheaper.
Amazon is a luxury, not an essential provider.
This depends on the country. In Poland most people buy online these days, but we all use postage boxes(company called InPost). They have 'boxes' everywhere, in every city, even small villages at this point have at least one, big cities have them everywhere within walking distance. They batch deliver packages to those boxes which is also more efficient and environment friendly, you get a code and can pick it up within 48hrs. They revolutionized online deliveries in Poland, noone wants to use a regular courier or postal services anymore. Having to sit at home, often not knowing when the courier will really come is tiresome. People just pick the package up along the way to/from work, groceries etc.