Bitcoin is not designed to be owned by everyone in the world. They are limited in supply but that doesn’t mean it will not go round the 8.1 billion population in the world if everyone decides to own a fraction of it. mBTC exists, which are smaller amount of BTC just like we have cents to dollars. If you own a 0.00000001 amount of BTC and can be amounted to a price, I think you’re already a owner of BTC in your possession.
Bitcoin is not limited to younger people only, even the older ones can own BTC and we’ve had of cases of such before. What matters the most is that they understand what bitcoin entails and how it functions, paying concern to their privacy and security of coin. I feel when they’re able to have total control of this, there age doesn’t matter anymore in owning Bitcoin. And I can’t imagine how poor someone can be that they can’t afford even a dollar worth of BTC if they really want to.