It is actually impossible for capitalism to address the problem of housing affordability, because embedded in the nature of profit-seeking capitalist activity in property sectors are a set of conditions that make it impossible to make profit out of low-income people. You are trying to square a circle there - relying on them supplying housing is never going to work. It doesn't matter if your in Harare, or Mumbai, or Rio de Janiero or Chicago or London - this repeats itself over and over.