Are you suggesting some sort of means test before you can own property, and if "society" doesn't consider your purpose just that it be prohibited?
As an immigrant myself, I don't get this country's obsession with stripping the developing world of its young adults. With the economy moving away from blue collar, semi and low skilled work, with jobs like warehousing, trucking, restaurants, etc. moving towards automation or labour reduction what are we expecting these newcomers to do? And forget about population decline, it's happening regardless, globally, so the world is going to have to settle with this reality.
If I was a millennial there's no way I would stay in the GTA. This is a huge country, and if you look at job boards there are jobs in the hinterland. Our immigrant forefathers had to leave their families and origins to find property elsewhere, but the idea of leaving our parent's home in our 20s is anathema to many for some reason.