This is a good question.
Once the courts discharge your debts, you can get normal (albeit with a low limit) credit cards, secured credit cards (cash security deposit as collateral for the credit line), and (most dangerously) an authorized user on a non-bankrupt person’s credit card, payday loans and cash advances, and personal loans. Some store-specific credit cards may not check your credit as well.
The APR on some of those small payday loans or cash advances are 300%, 500%, 700%, etc. Their business goal is to charge as much interest as possible before their customer heads back into bankruptcy (in which recovering their loan + interest would be difficult). It’s really scummy shit, but it’s been around since the beginning of time.
As you can see, the cycle of poverty is really difficult to break. Most people need credit to survive in the U.S., but getting good credit requires opening oneself to risk. If you aren’t financially responsible or if you have very little wiggle room for an unexpected charge (e.g., a car accident, job loss, etc.), you can go down the drain quickly.
Hope this helps!
Here’s a nice infographic on Chapter 7 and Chapter 13 bankruptcy.