A big part of the reason that nothing ever changes is because it isn't profitable for things to change, at least not when some moneyed interests can make a profit doing things like predatory lending and others get to have cheap employees.
In other words, the lack of a social safety net isn't just some accident that citizens blundered into. It was engineered and continues to be advanced by the people who make money from it.
I think there's a middle ground between "unrestricted predatory lending" and short term lending. The payday loan industry spends a lot of money on lobbying to push things to the former end (see attached article about 1000% interest rates), and have been very successful [1]. (But the overall lack of a social safety net in the US is due to moneyed interests that go well beyond the payday loan industry.)
Yours is a typical HN binary take that holds a thing must be an utterly unalloyed good or it must be banned, there's no middle ground for a thing to be useful when moderated and regulated, and predatory in other circumstances. This is a very common intellectual failure mode.
In other words, the lack of a social safety net isn't just some accident that citizens blundered into. It was engineered and continues to be advanced by the people who make money from it.