And when the "non-investor" landlords raise their prices high enough, they quickly find they have enough money to consider investing in a second rental property, out bidding people who have trouble saving after paying artificially inflated rent.

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.

https://www.wikiwand.com/en/The_Landlord's_Game

non-investor landlords

Isn't that an oxymoron? A landlord is by definition, an investor. Maybe you mean something else...