"Slumlords require a limited supply of local housing to gain leverage. " Indeed - if you want to get rid of slumloards then how about getting government out of the way of new housing being created? San Francisco is the poster child for how utterly draconian zoning laws screw everyone, but lower income people disproportionately.
It wasn't "getting government out of the way." It was literally government working in tandem with the trade-union interests of finance, insurance, and real-estate to preserve the value of the "asset," real estate. The problem is BOTH the government AND allied private industry working AGAINST the interests of their constituents and clients. The correction here will be MASSIVE.