The problem in essence is that property owners would rather leave their property empty than to accept less than market value for rent. The question is not “no rent”, it’s “less rent”. Virtually anyone you find sleeping rough on the streets is going to have *some* degree of walking-around money, hardly anyone has literally *no* money. But, the owners of housing don’t want that money, they want market value. They believe that a better offer will come along, and if they accept a low offer they will miss their opportunity for the high offer. It’s a failing of people’s payoff-to-probability calculation.
And also it’s a failing of core concepts of how contemporary capitalism is executed. Not to go too deep into it, the crux is this: If they accept a low offer, their property is worth less. If a fork is sold for five dollars, it is worth five dollars. If a fork is sold for five cents, it is worth five cents. So marking down the rent on a property depreciates the property, marking it up appreciates the property. Because value is determined by common belief rather than any concrete consistencies, sellers try to fix the value of property high and buyers try to negotiate value low. So if one party wants to raise their profit, and one party wants to not sleep on a bench, they have similar ability to set the price but wildly disproportionate levels of need. It’s a conundrum, and there’s virtually no way to feasibly and achievably solve that problem.