So here is a nice discussion of San Francisco's idiotic rent control law. It points out that in addition to the normal outcome of ultimately higher rents and fewer apartments being built that San Francisco has gone so far as to produce an even more perverse outcome: people with existing apartments opting to keep them off the market altogether. It is one thing to discourage people from building new apartments, it is quite another to discourage people to, in effect, destroy them.
One of the things that drives this the lazy assumption that the landlords are the oppressor class and the renters are the disadvantaged. It is probably true to a first approximation that those who own rental properties are more wealthy on average than those who simply rent them, but there is a lot more to the story and a large part of the groups concerned that do not fall into that picture.
Landlords are often working class people that have pulled themselves up by their own hard work. A large proportion of them are first and second generation immigrants. It is one of the few ways that a person with limited credentials and language abilities but lots of practical wisdom and willingness to work can get ahead and own something. A significant part of renters are young professionals who have a comparative advantage in manipulating rules and legal systems. What we reflexively assume is a contest between a white rich guy and a poor suffering worker's family are often the reverse, a first generation working family trying to get ahead by taking risks to reclaim urban areas through sweat equity being exploited by well-connected yuppies.
I think that is especially true of San Francisco.