From the two books I have read about Luciano, multiple businesses were established to handle all aspects of the bootlegging/cutting of the booze (bottle/label makers, trucking companies, etc) so it's likely Luciano and Lansky made a fortune over the long run (and if I remember correctly Costello even was involved with a legitimate liquor manufacturer after Prohibition). But once the government started cracking down, all of those investments evaporated and left Lansky crew-less and with no income stream.