That’s simply because young people know where the world is heading these days. They know that cryptocurrencies are our future. They like the fact that they own their money because cryptocurrencies are decentralized and there is no involvement of the government.
Apart from this young generation look for a way to keep the holdings and investment in a secure way than on inflated fiat. For some reason the purchasing value of USD decreased with time, but that doesn't mean there is no economic growth. But the growth gets slowed down. As the dollar value is tied with gold there is fluctuating economy.
Maybe these reasons can also trigger young generation to have an interest over crypto investment compared to the traditional investments.