Addictiveness isn’t the primary issue with drugs. Caffeine is quite addictive (61) almost as much as Alcohol (81) though notably less than Nicotine (100), it also has withdrawal symptoms, and occasionally people even OD, but it’s a also much safer because it doesn’t have significant health impacts or impare driving.

LSD is mildly addictive (18) slightly less than MDMA (20) or Marijuana (21). But MDMA is inherently much more harmful. That said, when LSD was legal it was quickly becoming popular and caused users a lot of issues. As such the more addictive nature of alcohol (81) is just one property and not enough on it’s own to compare it to other drugs.

Research by John Hastings. Relative rankings are definite, numbers given are (+/-)1%

While addictiveness is not the same as habit forming, it does link to overall useage.