There is a captive market for residential real estate, and a glut of commercial properties...
Everyone MUST live in a home while offices and other commercial spaces are a "nice to have" - so the businesses and individuals with extra capital have gobbled up the residential property to further push us into the "own nothing and be happy" economy.
I like the idea of transforming the old commercial properties to condos, but there's a ton of issues with retrofitting - which is the result of zoning and differences in building codes. Then there's the zoning issues themselves.
So.. as usual.. we are beholden to politicians doing the right thing for their constituents, and not their donors. These commercial properties are going to sit idle, and decay until it becomes a "true" crisis (buildings collapsing, mass squatting causing major health and safety issues) - causing untold costs to fix them to accrue in the meantime.
It'll never happen, but my grandiose solution is to deliberately crash the housing market via legislation limiting ownership of single family homes. This would boost the "velocity" of cash (lowering inflation), allows taxpayers to own (solves housing crisis), and would renew interest in the commerical real estate.