Here there's roughly 200,000 people who use amphetamines recretionally and about 20,000 people who according to doctors have a problem with their usage. I.e. 90% can use them occasionally without an issue. For alcohol the number here is closer to 85%.
It is true that many drug users never actually get their lives ruined over it.
But drugs are still negatively impacting their health, and there is always a risk of addiction forming and getting out of control.
I live in a country where drugs are illegal, but alcohol is "alright". Should I say people fuck up their health big time, and many, especially among men, do face issues with alcohol addiction? And those that go for drugs anyway rarely actually recover?
My take: people don't need drugs. People need an improvement in material and mental wellbeing, and drugs (and alcohol) are there as a form of escaping a poor reality. Drugs are just the way to make the world more bearable and "fun", to try to squeeze happiness from a grim reality, without thinking much of what it costs in the long run.
You're right. Poor living conditions(whatever this means) may bring you to use drugs to feel good. After the high ended you might want to feel good again(even if it maybe is just 5 days later) so you get high again. Once you start getting high periodically you're fucked. Eventually the time between each high shrinks. If you use Alcohol(which is a depressant) you will start drinking after it ended, because it make you feel like shit.
People who have a good living condition don't get addicted to drugs as easy as people with poor living conditions do.