Doesn't any landlord who defects from colluding stand to gain though? Like how Georgists argue that their land tax won't get passed directly on to renters because if it's applied to the whole market at once then absent perfect and universal collusion on behalf of the landlords renters will arb out those with the highest rent spikes.

Considering a handful of companies already control most rental pricing, and already extract "maximum value" from those properties, I'm not sure it would be any different in any direction.

I don't get why there isn't some level of Trust Busting going on regarding the rental property pricing management at all.