Didn't closing the books for twenty years damage the American mafia in the long run?

Closing the books at the end of the 1950s when the mafia was unknown to the majority of Americans and even after Valachi, thanks to Hoover who refused to investigate, didn't it bring any damage to the mafia?
Some small families arrived in 1976 with a few men of honor and a series of arrests was enough to decimate them.
Maybe if after Apalachin the Commission would prefer to allow the inductions or even cancelled the limit on small family membership the US mafia would be the shelf of itself today