Why make the act of consumption illegal? If I am a functioning alcoholic, and I stay at home and work, no reason to arrest me. Same is true with weed and all the other drugs. If I become a danger while intoxicated, arrest me for that. I don’t need a charge multiplier.
Technically, (in most places I’ve read about (in the US)) it’s not illegal to have it in your system. It’s illegal to be in possession of it. Presumably so people who OD actually go to the hospital.