> running out of people to kill with our indifference.

I wouldn't call it indifference. It's the drug policies that we've very intentionally adopted in the west that result in people purchasing from the black market. It's about as indifferent as the deaths due to denatured alcohol poisoning during prohibition when the additive was silently switched.

We know these policies result in mass deaths; we know other policies result in many fewer deaths; we choose the former policies.

I think that is partly because enough people consider those addicted to drugs to be subhuman - enough don't care much what happens to the addicted people. IMHO in that's because we a large political movement encourages indifference to those different from us, whether the difference is race, politics, gender/sexuality, nationality, or anything else.

What policies? Not legalizing heroin or other opioids?

I am not convinced we can claim what you think with any level of confidence.