The new laws did nothing to prevent this. They weren't meant to. We had a law designed to stop it that was enacted following the Great Depression. It was called the Glass-Steagall Act, passed in 1933. It was repealed in 1999 during President Clinton's administration... because Citigroup was too big to fail, and they promised to be good... honest.
2008 was an opportunity too great to pass up. Congress used the opportunity to enact a Federal bureaucracy that controlled banking and is not directly answerable to the Executive branch. This was the Dodd-Frank Act. Congress could have restored the rules in Glass-Steagall, which would have broken up Citigroup as a side effect. But they didn't.
Seems like recipe for disaster.
I'm sure that can't possibly go wrong. Especially since the entire SERP when I looked up the "non-prime" term you used was pages put up by fly-by-nights to reassure the suckers that there's nothing wrong with the paper and if anyone tries to tell you otherwise, you should probably punch them in the face.
(That hasn't been in the news for a few months, so I had to look around for some perspectives. Cf. https://daily.jstor.org/the-commercial-real-estate-markets-i... and, perhaps more controversially, https://www.propublica.org/article/whistleblower-wall-street..., suggesting that some of the same practices that turned the residential market into a crash-in-waiting may have been applied in the commercial market as well.)