There are also problems that can't be solved by businesses because they ARE profitable. For instance, a lot of aspects of poverty. Because people living paycheck to paycheck are desperate for cash and typically don't have enough savings to open bank accounts, they're easy prey for money lending at incredibly high interest rates - including payday loans and pawn shops; and for check-cashing services that take a signif…
Pawn shops and loan sharks are explorative. Yet, there has been much research done in recent years on the business of check-cashers and payday loans. They may appear profitable based on fees, yet the reason they charge fees or higher interest rates are due to the high cost of serving their populations. A higher risk of default means a higher rate of borrowing to compensate for the risk. Lisa Servon at Penn has done a lot of interesting work on this topic, and financial services for underserved populations in general: https://www.lisaservon.com