Things bounced back petty quickly. It only took about 80 years for us to start having access to good beer again.

More seriously - I don't think organized crime went away. It was a big problem before prohibition, and it continued to be a big problem after. However, it may have been weakened by the loss of an extremely profitable revenue source. Alcoholism dropped precipitously during prohibition, and started coming back again after it ended. Given that the US has a huge problem with drunk driving, one could probably make a cogent argument that, with the repeal of prohibition, we replaced a relatively small but sensational amount of organized crime with a large, but relatively socially acceptable, amount of disorganized crime. One might presume that other crimes that tend to go hand-in-hand with alcohol, such as domestic and sexual assault, also got a boost from the repeal.

I'm not sure how well any of this applies to marijuana. With marijuana, the worst (non-government-imposed) externalities seem to be related to how gangs behave when they're financed by the illegal marijuana trade. With alcohol, the organized crime was a problem, but the worst problems seemed (and seem) to be a direct result of how people behave when they've been drinking.

One common thread, though, is that opposition to both bans seems to be a reaction to government overreach as much as anything else. The penalties being handed down for alcohol possession were every bit as outrageous as the ones we see for marijuana possession nowadays, and that played a big part in public perception of the law.

This comparison isn't useful IMO because alcohol had actually been legal prior to prohibition introduced by puritanism. If anything I'd say prohibition gave people pause since alcoholism and heavy drinking was quite common prior to it being introduced. (Note: I'm not against marijuana legalization/decriminalization - just making an observation).