Ever since 1971 when Richard Nixon declared drug abuse as "public enemy number one" the federal government has spared no expense cracking down on the production and distribution of elicit substances to "prevent new addicts, and the rehabilitation of those who are addicted. Before the internet it was easy for the federal government to run propaganda campaigns and spread misinformation about substances to make them look far worse then they really were to scare the public into following along with the regulations without too much hassle or backlash for them. Some of the examples of the propaganda campaigns included, "Reefer Madness" a campaign stating marijuana would cause people to act wildly, commit violence, lose control of emotions, and eventually lead to incurable insanity here's the full hour long video 
In recent years the internet has taken a stand against the misinformation that has been spread and blindly believed over the years. Due to this fight against the propaganda the legalization of marijuana has seen an explosion of support and now other substances such as MDMA and Psilocybin mushrooms are being looked at for possible medical use. With the free spread of information we've been able to find that many of the "scary drugs" that the government had warned us about are in reality not half as dangerous as we were told.
Looking at the list of drugs in the "Schedule 1" classification which is defined as "Drugs with no currently acceped medical use and a high potential for abuse."
Some of the substances on this list include:
Heroin
LSD
Marijuana
MDMA (Ecstasy)
Peyote
Psilocyben (Magic Shrooms)
And Cocaine
Looking at that list only two of the substances have actually been proven to have a high chance of abuse (Heroin and Cocaine) while MDMA has proven to be somewhat addictive its been found to be far less that the aforementioned substances. Going beyond that psychedelic drugs LSD, Psilocyben, peyote, and even MDMA have been shown to be relatively safe as well as having medical properties. As far as Marijuana is concerned it has been documented many times as being a non-habit forming substance as well as having many practical uses. So why are these substances still scheduled the way they are even though they obviously don't fit the bill? Its because the truth about them hasn't been spread across enough people to warrant the federal government to reschedule or completely legalize them yet.
Now that you've looked at a handful of what the federal government views as the most "dangerous" substances you have to look at the punishment for them. In most states possession of a Schedule 1 substance is considered a felony and can land you up to two years in prison, in Texas possession of under a gram of MDMA can get you a state felony, a mandatory minimum of 180 days is county jail, but up to two years in prison, and a fine of up to $10,000. Under federal law possession of 5 grams or more could get you a sentence of 5-40 years in prison.
With a view on the severity of sentences it makes sense that nearly half of the prisoners in America are jailed for drug related sentences. The next thing to look at is weather the current system is actually doing what the government claimed it was supposed to and helping people recover from their addictions. Roughly 77% of people arrested for drug related crimes are likely to be re-arrested within 5 years of leaving prison. While prisons do have multiple rehab and substance abuse programs the Federal Bureau of Prisons admits that the number of inmates that receive treatment are low. In September of 2016 there were around 81,900 people in Federal Prisons or 47% of the overall inmates. That's a lot of people who had their freedoms stripped from them for a system that was never meant to help them. It also takes a toll on taxpayers seeing as the average annual cost to house a federal prisoner is roughly $31,997. Keep in mind that's only the cost to house them, that doesn't include the added cost of the DEA and special task forces designed to catch people who use and distribute elicit substances. As an average American footing the bill for these agencies and prisoners isn't the only way the war on drugs can negatively effect you, a law enforcement officer can use suspicion of drugs to illegally search you, drugs could be planted on you for a false arrest, you could get caught up in a bad drug deal, or you could be affected by gang violence spearheaded by drugs.
So if the Drug War doesn't rehabilitate addicts, or protect the public who does it protect? The only real answer to that is the politicians who play off of people's ignorance on the subject for votes and the big pharmaceutical companies. In later years we've seen the FDA and DEA try to schedule Kratom a plant from Asia that activates similar sensors in the brain to opiates as a schedule 1 substance. Their reasoning was because it is slightly addictive and 14 people died with the substance in their system over the period of years leading up to 2016. The main use of Kratom is to essentially replace opiates for pain that didn't warrant them, or it was used to help people with opiate addiction quit without getting as severe withdrawal symptoms as they would quitting cold turkey. We have also seen this happen with CBD a byproduct of cannabis was scheduled as a schedule 1 substance in 2018 even though the only use for the substance is medical uses, it's nonaddictive, and not a harmful substance.
Looking at the evidence the Drug War is a war against the people by a government that wants total control of the populations manner of thinking, the big pharmaceutical companies only add fuel to the fire releasing incredibly addictive prescription drugs without properly warning the patients who take them and making any products that could rival theirs illegal.
Thank you for taking the time to look at my first post, while it may be a bit rough I hope to improve on my writing abilities and expand further on similar topics in the near future.