You're over-emphasizing the methods by which these people are price-fixing, rather than the result. The result is a price higher than the market-clearing price that is low enough to find tenancy for all housing. Any scheme to generate excess profit by raising rent above this price is (or ought to be) illegal, whether it's colluding to do price fixing, using some algorithm to price-fix, or monopolizing the market.
The FTC is claiming the exact opposite, basically.
Colluding to fix prices, by any means, is illegal. It is still illegal even if the scheme is only followed by a handful of those who "agreed" to it. It is still illegal if it utterly fails to control the price and thus has no material impact.
It's like trying to scam people. You're not allowed to try to defraud people. It doesn't matter if your scam is so bad that it would cost you more money to execute than you would get out of it, and it doesn't matter if no one engages with your scam at all: what you were doing is still illegal.
FTC would not be interested if the scheme hypothetically somehow had no effect. They said that it is still be illegal even if it is imperfect. Empirical reality still gets a vote, for pragmatic reasons.
Yeah, there's two separate ways of thinking about law in general - mechanically about what the rules say, and politically about how the system ought to be influencing behavior. When the FTC or other prosecutorial/regulatory talks about charging people and alleging wrongdoing, they're making mechanical statements about how what they did violates the law. When they make decisions about who to investigate, charge, and/or fine, they're making political decisions about what constitutes wrongdoing.
> The result is a price higher than the market-clearing price that is low enough to find tenancy for all housing
This is impossible. If all the units are rented then by definition the market clearing price is being charged. The collusion comes when landlords start leaving units vacant.
All store owners should be jailed, then, since the presence of inventory on their shelves is proof of a scheme to generate excess profit by charging higher than market-clearing prices - or it would have sold already.
We only know current inventory. As I write this in early March stores are starting to order their halloween candy (the orders need to be in by somethime in april). You do not know what candy your competitor will order, but this is relavant to sales since you will price match their ads and in turn lower priced candy will sell in greater quantities.
