From here on is only speculation and I'll do a deeper dive when I'm not on a phone. I'd like to see the rest of the statistics broken down by offense. Additionally I suspect that drug offenses would lead to repeated incarceration and perhaps eventually worse offenses.
Most violent offenses are committed in the context of existing relationships though, so there are certainly non-policy and certainly non-drug-policy ways to address crime in the United States.
> From BJS [Bureau of Justice Statistics], [...] an incarceration rate of about 725 people per 100,000 population.
> Suppose every federal drug offender were released today. That would cut the incarceration rate to about 693 inmates per 100,000 population. Suppose further that every drug offender in a state prison were also released. That would get the rate down to 625
(It should go without saying that these are all simplistic lenses on a very complex, multifaceted problem, and in reality many parts of the justice system need reform.)
[1] https://www.bop.gov/about/statistics/statistics_inmate_offen...
Including "drug offenses" the U.S. incarceration rate is 693 per 100,000.
Excluding "drug offenses" the U.S. incarceration rate is still 625 per 100,000.
https://fivethirtyeight.com/features/releasing-drug-offender...
I agree with you that we should get the drug offenders out. But the characterizations that "most people are in prison for drug offenses" should be updated.