I would suggest that it won't matter WHAT percentage of the population "owns" the housing if there are more people looking for a house to rent than there is available.my point is that people that complain about our immigration numbers consistently ignore the reasons for them and just want a scape goat for the current housing issue that isn't landlords and related government policy
there are more houses being rented than there are landlords
home ownership is going down among owner occupiers
but home ownership is going up among the investors
when 10% of the population own 40% of the housing there is a problem that isn't about immigration levels
One way to reduce that imbalance would be, I dunno, reduce the amount of people looking for housing.
It's disingenuous to say that immigration levels aren't a contributing factor, they are by no means the only one though.