But then you're assuming that renters are living week-to-week. Which is most certainly not always the case.
I'm not yet 50, renting, and I could almost retire with what I have right now- due to living in a cheap place and wisely investing my money (which would otherwise have gone on a super-expensive mortgage) until it's grown into a very nice pile indeed.
There are some people that rent and blow their money. And there are also people that own houses and blow their money too.