If we accept that as true, then let the state build minimal housing for those who cannot afford shelter.
TBH, that still won't take away the buy-to-rent investors, because people will still want better housing than the state provides.
This will provide a floor for landlords to compete against and keep prices down.
The state/city could nationalize restaurants easily and and provide cheap or free food to those who want it
The state/city could nationalize Apple easily and and provide cheap or free iPhones to those who want it
Seems like we found the solution /s