Rent control serves as a means to add stability. If landlords could evict tenants without cause and immediately rent to someone else for $100 a month more whenever the market changes, they would. That's bad for everyone.
The problem is that when a tenant has been renting the same place for 20 years with the landlord raising the rent as much as legally allowed each year, and it's drastically below market rates, but if the landlord evicts them they can't rent to anyone else for a year. The solution to that is to build more housing to bring down market rates so that people aren't trapped in one place forever.
The problem is that when a tenant has been renting the same place for 20 years with the landlord raising the rent as much as legally allowed each year, and it's drastically below market rates, but if the landlord evicts them they can't rent to anyone else for a year. The solution to that is to build more housing to bring down market rates so that people aren't trapped in one place forever.