If someone is selling a chair and it's too expensive, you can simply choose not to buy it. If no one buys it, the seller must put the price down to something reasonable so that it can sell. This system works because people always have the choice to boycott chairs and sit on the floor instead when they're too expensive.

If rent is too expensive, your only other choice is homelessness which is dangerous, a health risk, makes it hard to stay employed and means you'll be harrassed by police. If we were legally allowed to boycott rent & go build our own houses on any available land using whatever building materials we could find, rent would go down. Rent is only as much as it is because we have no choice and landlords know it. That is why it's exploitation.