No. Landlords do not "produce" rooms by taking raw materials and transforming them into goods. In the current market, the rent is determined by how much the marginal renter is able to pay. Increasing the cost to the landlord doesn't magically increase the renter's ability to pay
Since institutional owners like this make up a tiny percentage of ownership, your solution would have a huge impact on small landlords, which would be passed along to the tenants.
Basically you're asking renters to pay for this behavior...
"A" government[1] could telegraph that major (as major as is necessary) policy changes are coming that will affect SFH investors in a detrimental way, and that it would be in their best interests to prepare accordingly.
If this does not happen, I suspect Mother Nature will eventually intervene, and that usually doesn't go well for anyone.
[1] I do not presume that any arbitrary Western government is actually capable of this in the real world as it relies on many prerequisites, some of them policy, some of them psychological/ethical.
I don't get this thinking. What is the difference between one landlord with 2 properties or 2 landlords each with one property? Why is the latter better than the former?
Does it matter? If you want to achieve maximum dwellings for renting, changing the distribution of units / owners doesn't seem like a practical way to go about it.
You would want to make more units, as many as possible.