The problem is that cash windfalls don't build wealth. You need consistent income to do much of anything in this world that matters that can be traced, tracked, expressed in credit reports and used to back loans for serious purchases like cars and homes.

If you simply gave young people $100k - which is a number nobody is seriously throwing around - what do you think they would materially gain from it? Very little. Their ability to purchase a home is still income-based and far more than a $100k windfall in many parts of the US can sustain for much time at all and everything else is just a slow bleed.