You consider countries in which the majority of households lack running water, electricity is available 20 hours a day if you're lucky, or where more than 20-50

You consider countries in which the majority of households lack running water, electricity is available 20 hours a day if you're lucky, or where more than 20-50% of the population work in agriculture (typical for industrialized countries is 1-3%) to be developed? Clearly they have no major infrastructure left to build and their industrialization is done. Nothing to develop left at all.