To spell it out, they seem to be completely ignoring that those rental properties are not vacant. Instead, they house people, just like they would if they were owner occupied.
20% of market capture does not cause homelessness, but there are many very valid arguments that treating housing as an investment isn't a stairway to ending homelessness.
Turbo Greed (acquire all the things) and lack of monopoly protection and enforcement.
If we're going to tackle homeless, we have to remove systems that incentivize the collection of homes as a financial asset. Make more homes by one person or entity less desirable or simply undoable.
Turbo greed isn't a thing. And if you think there's a monopoly in residential real estate ownership, you have an absurdly broad definition of the term.
Instead of trying to manipulate a market through yet another layer of regulation, you can just let builders build more.
If turbo Greed isn't a thing, why do the 830+ billionaires in the United States control more wealth than the bottom 50% of the population?
And, why did we just give them a YUGE tax break?
"Build more" is not an option, because the incentives don't align to solve the problem. The things getting built are built to capture margins and not to solve the housing problem.
You're missing the point, which is that adding a superlative in front of a concept you don't like doesn't make it more important or the problem more severe. And your reductionist take on wealth distribution isn't even worth discussing.
Build more is the only option to actually fix the problem. The incentives could not be more aligned between home builders and home dwellers. Builders want to build, and there are dozens of them in all major metropolitan areas. Home dwellers want shelter. Sounds like an ideal situation to keep margins low.
More regulation == more regulatory capture, which your kind supposedly doesn't like but you don't seem to be able to help yourself.