Landlords raise rent by the max allowed because they can. There is no “catch up” because the purpose is to protect renters against huge jumps.
I think rent controlled units that sit empty should be subject to a tax based on an escalating percentage of the market rent. You can own property to rent out, but in a city with a tremendous shortage of housing, you need to rent it out.
I lived in a building with affordable housing units and management decided they would rather not rent them out at all. Horrible.
They would just be taken off the market and then relisted later.
Forcing people to rent their properties and also forcing the price isn’t something I can get behind. People need to be able to choose what they do with their property.