It’s not a massive difference just a rug pull at a higher conceptual level (informational) because the obvious financial rug pull was done a hundred years ago and has since been regulated.
Almost everyone who has lost their shirt in financial derivatives in the past 50 years could have learned about the risks they were taking from some text in a prospectus somewhere, but chose not to.
For example, people who lost a lot of money holding XIV (a leveraged inverse-VIX ETN) had the warning about not holding the thing overnight in bold red text in the prospectus. People holding leveraged CDOs and every kind of CDS had all kinds of warnings in big bold text in their prospectus. The good old "liar's loans" of the early 2000's had big bold text saying "it will be bad for you if you lie about your income."
Pretty much the only financial products that don't come with big bold text saying "you are an idiot for buying this" are single stocks and the most boring of ETFs/mutual funds (eg SPY).
Contrast that with the warning signs from crypto projects, which are a lot more oblique than big bold text in a document that they tell you to read. Wall Street screws you, but they generally do it slowly and they tell you how. Crypto projects just straight up steal your money one day out of the blue and run to Dubai.
The rating agencies did not understand the products they were rating. However, the warnings were almost certainly on the label.
That's why the rating agencies were sued over this, and not the banks.
They did sue the banks. For many things including inflated appraisals of the loans.
I'm sure they have some kind of warning for everything that isn't FDIC insured. But misrepresenting high risk as low risk instead of zero risk is just a quantitative difference. There are plenty of scams that do this. for example just lying about a company's earnings. I suppose the precise crimes they charge them for may differ a bit.