Perhaps property sales and rentals should require attestations about who offered what price and we can use that data to consider deterrents or levies on those who moved the price up from the prior owner or tenant. Sure there are some prospective occupants that will say a higher price just to skip the queue, I dont think they are really the majority of people even when well funded transplants descend upon a town. I think the majority just take whatever the landlord offers.
Taking the price offered for a particular property is not the same as ignoring prices. Apartment shoppers search for the combination of quality and price that best satisfies their preferences. I have a hard time imagining an alternative. Would that be going to an apartment search engine and simply picking the first result, regardless of quality and price?
When I go to the grocery store, I don't negotiate with the cashier. That doesn't mean grocery stores aren't competing with each other.
If a landlord chooses to consistently rent below market rates, for whatever foolish reason, then they'll probably wind up selling the building to someone who knows what the market rate is. It might take a while, but it'll happen eventually.
I agree with most of the rest of your comment, but none of that means that the landlords are price setters.
Nor does it show that discussing supply is a "deflection."