Madoff faced a straightforward case. He was the proprietor of the largest known Ponzi scheme in I think the history of the world. Notably: running a Ponzi scheme is already clearly a felony; no novel or even interesting theory of law was required to charge him (for Mail Fraud, Securities Fraud, Wire Fraud, and Money Laundering, among others).

Even then, the sentencing guidelines complicated things for prosecutors. None of the offenses Madoff was convicted of carried a life imprisonment sentence, but the sentencing guidelines calculations called for one, which meant he had to be charged with the statutory maximums for all his offenses.

My point isn't that the Sacklers couldn't be charged criminally, just that the rules for doing so are complicated, and prosecutors can't just make them up. A not-unlikely result of trying to secure a 150-year sentence for a Sackler is that they might simply win the case.

If you have a theory of how the Sacklers and their henchpeople could be made to face decades in prison, a straightforward way to articulate that theory would be to cite the offenses you'd see them charged with. Then we can look at the jury instructions for those offenses and see how difficult it would be to convict them under those offenses.