Absolutely correct. When prices go up, newer tentants end up subsidizing squatters who are paying below-market rates. If rent prices were variable then the market would be more liquid and the total supply would be higher, and thus new rentals would be lower.

I guess it's nice not having your landlord jack up your rent each year (and landlords can't price little grannies out of their homes). But you also get stuck in one apartment because the cost of moving keeps getting higher.