“Capitalism” can neither fail nor help people. It’s just an ideology, and it isn’t the one you (or most of America) apparently think it is. Capitalists believe that accumulating capital empowers them, and only people who can accumulate capital can be “capitalists.” People who blindly believe in them are just fools, not capitalists. As you have pointed out, very few Americans are accumulating capital. Most are just living in debt.
What has failed the young is not capitalism: it’s Consumerism: the belief and activities whereby all resources are to be purchased and consumed without replacement. Capitalists have built a selfish system for themselves inside the blind consumerism addiction of masses of people. The actual modern version should be called “consumptionism”, because it is much like the Spanish Empire after it acquired too much gold. The living activities of natural humans and social humans (“civilized” if you will) are usurped by perceived purchasing power to the point that they cannot function without money. They don’t believe in money or have a lot of money: they just depend on it for basic functions of life, and losing it means starvation and death.
Almost everyone knows we have this condition, and that’s why the politicians work so hard to cater to the desires of capitalists who DO control the money that everyone needs to live (in this system). That said, it isn’t capitalism except for a very few capitalists who have a choice. The rest are enslaved to consumerism and if they spend their energy fighting capitalists, they will not solve the consumerism problem, which is more insidious and personal. The cure is to live without the capitalists first (Soviet communists were elite capitalists, too). Needs must be met through cooperative local systems of labor, food and civil infrastructure. It has to be sustainable. That means the labors must add more to the environmental resources than we take away, and any technologies must be maintained with local resources (a farm, a city, and a house are technologies).
As long as everyone argues over where the Capitalists’ money is going, then people will be worthless to each other, because they will continue to believe their lives are granted from ‘on high’. This is why Capitalists are so friendly with religions. It’s the same old system, just bigger and more complicated, that we have had for thousands of years.
The rich get richer because the rest believe they have to work for them and buy their stuff.