I suggest checking out The Emperor Wears No Clothes for a background behind the start of drug prohibition as a new way to discriminate and make use of bolstered police forces after the failure of alcohol prohibition, as well as prevent the disruption of several entrenched industries.
It's a short read, extremely informative, and it's available freely online here: https://jackherer.com/emperor-3/
> Go be genuinely poor, it's really easy to do. Just use a tiny amount of money to live off of. And see if it causes you to commit crimes.
That's not the correct way to look at it.
We are artificially creating crimes from things which shouldn't be illegal and which infringe upon basic freedoms, and then creating the conditions that lead to people committing those "crimes".
"Show me the man and I’ll show you the crime," as Beria says. The Drug War is a tool to, among other things, benefit the new tax-supported slave trade disguised as a private industrial prison system. Affluent citizens are usually able to circumvent the system, as designed, and thus these laws are able to discriminate against the poor while seeming "fair".