It's right there in what you have written yourself. 31% is a finite number, that means scarcity. 16 million homes is a finite number, that means scarcity.

In a world without scarcity you'd have infinite food and infinite houses. We do not live in such a world.

You don't give people without the ability to pay for things stuff for free because you don't want to absolutely wreck your economy. If I'd get food and housing for free, I'd be the first one to quit my job and just live the good life of not working ever again. I'm incentivized to work because that isn't the case. And also because it's such a stupid idea, that I can see that it would collapse fast.