>Humans love alcohol-like feelings, so the comparison is vis-a-vis against alcohol.

Some humans love the feeling of being in an inebriated state commonly brought on by the use of alcohol. The amount of people addicted to other drugs shows it is not just the drunkeness of alcohol people are after. However, the simple fact that alcohol is legal and readily available means that's the thing people use to achieve this inebriated state. Allow other substances to be legal and destigmatized the way alcohol has been, and you will see numbers change.