> At least in the US this happens due to rent control rules.

No way, the vast majority of the US has no rent control at all. Landlords can already raise prices whenever they want, it's always been legal. Despite this, most choose to put in 10% to 40% increase, every single year, anyway. - https://www.michiganpublic.org/economy/2023-03-22/as-housing...

> If they knew they can raise prices when needed, they could afford to lower prices in a downturn knowing they can raise later.

The only time a landlord will lower prices, is if a downturn is so severe that the Federal Government prevents landlords from accessing credit to wait out that downturn, and the landlord risks having to actually sell the property. (Which after 2008, it seems unlikely that the Feds would ever let the market correct again)