When investors buy properties and set higher rent prices, non-investor landlords raise their rent prices to whatever the artificially-inflated market rate is for the area. Not all 1.4 million landlords have to be actively working on fucking the populace, but they all end up participating in it because no one is going to charge lower rent out of the goodness of their heart.
Did you know that the original version of Monopoly was called “The Landlord’s Game”, and was used as a teaching aid to teach the poor about the inherent immorality and inevitable loss of freedom and equality land ownership entails? Then a capitalist came along, stole the whole thing, rebranded it Monopoly, and made a shitload of money.