Most landlords arent big corporate in the USA either especially in areas where the housing crisis is the worst.
I think this narrative is just meant to distract people from questioning the necessity of the landlord class, they want people angry at a faceless corporate boogieman instead of local landlords (for obvious reasons)
Rental prices are set at the edge, so you only need to own a fraction of the market to drive rent increases. Corporate landlords absolutely do this.