You are using emotionally charged words ("artificial", "abuse", "greed"), which makes a bit hard to have a constructive argument, but let me try :).

One way to think about prices is as a signal. When greedy landlords raise prices, they send two signals: (1) To other landlords and wanna-be-landlords, saying it's an attractive market which would justify new construction or cleaning up your spare bedroom and putting it on the market, both increasing supply, and (2) to current and future renters, making it more economical for them to move elsewhere and thus save on their rent, thus reducing demand.