Higher taxes is just a cost of doing business which is passed on to other tenants, be it long or short term rentals, even if housing stock is temporarily held - though I don’t disagree that such a vacancy tax is a good.

GP was right - forbid corporations from owning any residential property if 4 or fewer units and greater than four unless the building is wholly owned.

On the tax side, add a purchasing tax of 15-25%, 90% of which is rebated at closing for non-corporations who have not received the rebate in the previous 24 months. That targets flippers and property-bros willing to go naked on liability.