I would argue this is actually a separate thing. Rent control does one thing. Zoning laws like they have in SF that prevent building more dense structures preve

I would argue this is actually a separate thing. Rent control does one thing. Zoning laws like they have in SF that prevent building more dense structures prevent people from selling in one area and then finding a new property that is much smaller in the same area. The combination of rent control and NIMBY zoning laws makes downsizing challenging.