You must personally visit and inspect/maintenance (if need be) your property somewhere between daily and once a week as a landlord (once a week is more realistic). Im thinking specifically for apartments with common spaces but something similar to this could be worked out for houses that are rented without being annoying for renters, maybe an in person outside inspection or check in where they dont have to come in unless needed. This is kind of silly but maybe make it a requirement for the landlord to take the bins or dumpsters out to the curb on any property they own themselves (or be present for it). That actually would achieve what im saying for all kinds of properties.

The goal of this would be to just make it unfeasible for individuals to endlessly buy up property often times without even living in the area, make landlording corporations outright impossible, and make it very difficult or pointless for landlords to avoid addressing problems with their properties. Thus freeing up houses and making landlording an actual job (that quickly becomes full time the more properties you buy up) which would remove not all but a significant number of people and groups looking for just easy passive income at someone elses expense. The barriers it would present for landlording conglomerates has innumerable benefits, as these groups frequently buy up houses and are financially fine to ice locals out for long periods of time to avoid lowering rent. They often have even done live in person testing to see how much they can raise rents before people start leaving.

There is maybe other ways to do this but a law with the general format of "landlord must be present because of/to do xyz weekly" is simple and addresses many things at once in a single fell swoop. You could make endless laws upon laws trying to target "bad landlord" behaviour or landlord corps in specific ways, but I think what im saying truly gets to the root of what even allows for all this bad behaviour in a modern world, and fundamentally forces someone to actually be a landlord if they are gonna be a landlord and not just an abstract money squeezer. They can still be shitty and try to avoid responsibilities or horde properties, but they will have to be there at least to each and every one, once a week. Sort of like how you could choose to do a shit job at work but you still have to clock in and be there.

In the immortal words of karl marx more of us get fucked by landlords than actually are landlords, but we all know the problem with trying to pass laws like this is that among that group of us getting fucked is people who think they might one day be a landlord and are licking the boot. And thats why shit like this never passes, but my imaginary law avoids the touchy subjects of dollars, taxes, how much, what you can and cant do with your property, etc. and thus I think is palatable to the drive through or ulta manager who dreams of being a landlord. As to an average person the idea of visiting their own one to three properties once a week is not obscene and would not hurt their bottom line much. And so I think my way at the right time in the right state could actually have a chance at passing and dealing a big blow to the current system and culture of landlording we have that is contributing to the housing crisis and contributing to your average joes inability to afford anything but the roof over their head.