Why do we need to alter our mental status with chemicals at all? How healthy is any of it in the long term?
Peer pressure? Commercials? "Cool guys" in the movies and on TV. Youths trying to be "adults?"
Caffeine is good if you need to stay awake or an extra boost of energy, cannabis is good to help fall asleep, amphetamines are good if you need to get a project done on a short timeline, alcohol is good to help overcome social anxiety, psilocybin can be good to help get over other addictions and bring about a fresh outlook on life. I could probably find uses for any others.
Probably not good to use any of those daily or even weekly but they can all serve useful purposes on occasion. Also I think it's helpful to try low-moderate dose of most drugs just to see what it does. Its interesting to know first hand what the difference between a dopamine rush and a serotonin rush. I like having a first hand idea how x drug they're talking about in the news actually affects you.
Michael pollan just wrote a good book about why you should try psychedelics, it's an interesting read if anyone is curious in a case for altering your conciousness.