if anything I would say RICO broke the mob's back
I'd say that Italian-American assimilation did more to break the mob than even RICO.
The mob has adapted somewhat to RICO, but it cannot adapt to the assimilation of Italians into the mainstream of American society. Though of course RICO has probably helped speed up this assimilation in that it likely works as a strong disincentive for getting involved in OC to begin with.
It's complicated. Like you said, it's silly to pinpoint one specific guy, or even numerous specific individuals.