Problem also is the "junk" deposited under and around the buildings = Pests, rats and vermin, disease and sewage-human waste-kitchen trash discarded in and under and around the steel boxes. The corrugated outside walls and roofs and floors are perfect breeding grounds and housing for these pests.
Regrettably, the actual users of these apparently "cheap" housing units are seldom (if ever) able to/willing to/trained to keep up and keep them clean and pest-free. Too often, the "government officials" offering such free housing/temporary housing units are themselves corrupt and don't properly use and spend the maintenance and upkeep money (goes instead to bribes, other officials, or miss-use), or the money is one-ended (funds are granted to provide the units, but not maintain them or provide water, sewage, cleaning, and sanitation needs for the long-term.
Can they work in theory? Yes, absolutely.
Do they work in practice? No. They become new slums and hovels and expensive, rusting huts inhabited by ever-poorer people in ever-worse conditions.