1. Cost of housing.
We mostly don't have affordable housing. This is a serious burden for many Americans. It's not legal to live in a hut without electricity or the like, even if you wanted to.
2. Our public transportation and walkability sucks.
Most Americans need a car. This is a huge financial and logistical burden for many people.
3. Healthcare
The US spends insane amounts on healthcare and people who are poor let problems linger because they aren't sure if it's worth getting seen and having the bill for it.
I've escaped that pattern. It was really challenging to escape it and I've been dirt poor a long time, in part because not having a car is a logistical barrier to earned income and even if isn't, it's a social signal that "I'm an incompetent loser" which helps suppress my income.
I'm gradually making progress on all of it, but it is tough to swim against the tide and our current tide is highly problematic and burdensome for most people in the US. So it's a damned if you, damned if you don't situation.