Removing impurities is really tricky, but that said, it's not like industry grade equipment and operations are being used here to manufacture it. There may be a simple step or two that would help significantly reduce impurities.
Your comment also made me realize for the first time, a lot of these illicit drugs are made by hobbyists, so to speak, not professional manufacturers. Just knowledge isn't enough, and I say that as a chemical engineer. If I tried to synthesize anything at home it would have a high degree of impurity -- even if I bought some nice lab equipment.
There's probably a lot of benefit in having the government subsidize a pharma company to make high purity drugs. The impurities could be responsible for a lot of side effects.
I bet many go out of their way to avoid getting proper equipment because those purchases can get them on a list. It's legally safer to produce sketchy shit, and since you're breaking the law anyways, who cares if what you're selling is really what you say it is.
Profit comes from volume, you can take the risk of selling to as many people as possible or you can inflate your volume with other cheaper shit and never even consider the bit of powder that remained in a lethal dose-sized clump as you mixed it.
That's like saying that the best way to reduce harm from alcohol is to make good strong alcohol cheap so people wouldn't drink eau-de-cologne and denaturate.
Problems with alcohol are not limited to it sometimes being mixed with poison.
Problems with cocaine didn't start with it becoming illegal.
Let's please not talk as if it's normal to consume it.
Tell that to my two infrequent user friends who decided to share some cocaine at home, after going out the bar, catching up after not seeing each other for a while who both died from fentanyl overdose.
Inert cutting agents that simply dilute the product are not type of impurities in the sense that I was talking about. And I think there’s clear.
Also. when inert cutting agents are used without the user knowing the potency they are more liable to overdose. Legal and regulated cocaine would not have fentanyl or levamisole etc, and the potency would be printed on the bottle.