Yes, I would also remove investment property tax benefits, were I emperor, but it would not cause rental rates to rise. That's not how the rental rate is decid

Yes, I would also remove investment property tax benefits, were I emperor, but it would not cause rental rates to rise. That's not how the rental rate is decided. The rental rate is based on vacancy and income, ie supply and demand. If rental is harder to make money on, the only effect will be to drive down the cost of the property as the actual number of houses is fixed.