Imagine that “free plastic bags” had never been a thing.
There are homeless people without adequate toilets. Would you suggest “let’s fill our world with heaps of littered plastic bags, because some homeless people might be able to use them as portable toilets” as a remedy?
Yeah, instead we would have no solution at all and would just consider the higher amount of disease to be just a part of life. Homelessness isn't a new problem, it's simply one we don't do anything about. So these ideas of "we could do X to fix it" don't matter. We're not going to do them.