Also rent control should not be the only measure. The county should also buy up housing and rent for cheaper to drive the market rate down, price gauging should be illegal (for everyone, not just foreign investors). etc.
Almost, buying up housing is fine if the government changes zoning and upzones existing properties. It is better to go one tiny step further and make the government guarantee housing for a fixed price because then it is truly forced to fix the problem.
Once you have done this important step the government has many options. It can either fix the demand side or the supply side.
The supply side is easy to fix by changing zoning laws to encourage taller residential buildings and then by actually building them.
The demand side can be fixed by changing the tax law so that commercial property is no longer the only source of property tax income. This lead to an imbalance of commercial vs residential property which then lead to lots of workers without housing which then lead to a race for apartments driving up prices.
Lets say that everything gets converted to rent-controlled in an area. A child becomes 18, graduates from high school, and wants to stay close to their family to maintain their emotional connections. If everything is rent-controlled, but not enough housing is built, they have to be on some sort of waitlist or lottery to stay in the area. This will push out so many people.
The only solution is to make enough housing for the people that want to live in an area. Without that, we are rationing it by price, by lottery, or by waitlist, and all of those will destroy the emotional connections that both you and I want to maintain.
But it's only one, very small, tool in the arsenal to make cities work for the people. It must be accompanied by robust protections to new people as well. The flaw with rent control in isolation is that it assumes that people never move, are never born, and never die, and that cities never change. In order for rent control to be a useful tenant protection, it must be accompanied by robust rebuilding when more people need to live in the city.