While there were worse bosses, Vito Genovese and John Gotti were really instrumental in blowing the lid off organized crime and allowing law enforcement to build cases, hand out indictments and in the latter's case, use RICO convictions to dismantle rackets entirely. Both of their leaderships caused major blows to LCN and even if they weren't the worst (they're admittedly well known and fascinating to study), their successors should not look at their reigns as a net positive for the mob.
This. Gotti was the worst, because he had something to lose. For the bosses out west the risk far outweighed the reward. The feds would have just loved to list people as "LCN" members and boost their morale by hitting them with RICO charges, all for some small time gambling operations? I'm sure some guys got involved with the cocaine trade that was in full swing by the 80s but that only brings on stiffer sentences. By the 70s it was time for the families out west to cash out. The blood offspring of a lot of these guys own legitimate businesses now and are doing well. Especially the San Jose and SF families.