With housing shortage in many parts of the world, could this be a solution for the poor?
You could even stack them on top of each other like marbles (assuming an edging so they don't roll off), and be able to use a very small space for hundreds if not thousands of dwellings.
Electricity and network could be done by using a meshing technology.
Also, "cheap housing for poor people" has a bad habit of becoming "projects".
And of course there are also some high end options that are popular for building bespoke houses in e.g. the Scandinavian and North American markets.
Basically, pre-fabricated housing is a solved problem from a technical point of view. Cheap to manufacture, easy to deploy, and pretty comfortable to live in. If you think about it, there are numerous viable ways of providing people with some form of shelter to shield them from the elements.
Mostly the issue is not technical challenges but the fact that there's a lot of local push back against the deployment of any form of cheap housing projects in a lot of places. This has nothing to do with their pricing (cheap) or quality (pretty decent) but with the level of protectionism in place to guard prices of existing houses. Solving cheap housing would collapse prices.
That's why you don't find trailer parks in richer parts of the US. However, they are very popular as semi-permanent slums in less rich parts and have been so for many decades. Tens of millions of people live in those actually. Just mostly not anywhere near where the housing shortages are the most urgent.
You can load them onto anything that can transport such a container, nothing exotic or problematic, just run-of-the-mill reach stackers, trucks, ships, etc. They are cheap because 40ft-containers are mass-produced, and you can make them either out of new cheap container parts or reuse an old one into a home. Electricity is usually a 32A-3phase-CEE-connector in every corner which can also be used to chain multiple containers. What is trickier is fresh/waste-water connections, but also not really a huge problem.
Biggest problem with those right now is that manufacturers are overwhelmed due to demand for refugee housing in Europe.