It's just a single study right now but the results are interesting. While investor bans increase first time home ownership, those buyers were often much wealthier than the renters they were replacing. So while more people owned homes, those homes went to the richer people and the poorer ones were forced out of their neighborhoods due to rising rent.

The ban has successfully increased middle-income households' access to homeownership, at the expense of buy-to-let investors. However, the policy also drove up rents in affected neighborhoods, thereby damaging housing affordability for individuals reliant on private rental housing, undermining some of the intentions of the law

The logic at least makes straightforward sense to me. The people who can afford to just straight up buy homes are obviously going to be richer than those who can't so when the rental potential is taken away, they all go the richer buyers