I believe a landlord should have a similar stake in their property that franchisee's for good companies often have: Forced to have a very real presence and understanding of the property, its condition, and how to handle the work if necessary. This would force landlords to own only so many locations, often closer together, and would create more landlords of higher quality, which means better living conditions, and likely lower rent for tenants. This would also make it more of a job. I feel it would also be beneficial if there was a subsidiary program so that landlords were forced to rent, at reduced cost supplemented by the Government, individuals with disabilities that don't directly impact those around them, who can largely live on their own, though may not be able to hold a full-time position. This would only have to be maybe one unit out of every 10.
Finally, assuming everything above could be ironed out to work without some jackass finding loopholes: Property owners, regardless of location, should be forced to pay taxes unique to them. These taxes would specifically go towards programs that support housing and relocation efforts, food and clothing programs, and especially help to offset lowered cost-of-living rental units.
We can mix and match these ideas. I'm mostly vomiting them out this point. POINT is, they can stick around. Let them feed off my wage ONLY if they make it worth our time. I'm happy to not have to worry about mowing a lawn or shoveling, for instance. But if they are going to exist, they must do so under rules that make it more work and less play. After all, a landlord who goes out of their way to promote strong living conditions and happy tenants would, using the ideas above, be a landlord who could play more. Because they've earned it.
Unlike now where the good is uncommon.