> Productivity increases -> wages go up -> "30% of salary on rent" goes up -> rent goes up -> cost of everything goes up

Yes wages might go up (someone who can use Sharepoint[0] is probably more efficient than someone who can use a physical filing system) but you need far fewer people to do it. So costs can still go down.

> We could arrest pretty much all cost of living growth if all renters (both businesses and individuals) just decided not to continuously agree to pay higher prices for the same land/apartments/buildings.

I agree that most of cost of living is housing-related, but rent price increases are a function of population increasing faster than housing. That's the thing to address.

[0] or something good