Here in Brazil the drug dealing is really really intense. The government can do nothin about it because of the large amount of "milicia"(corrupted cops). If marijuana was legalized, the government could collect taxes on it and reduce the number of milicia. Milicia are only milicia because of the extra money they get with drug dealing.
Besides that marijuana has a lot of
health benefits, if it was legalized the government could set the maximum amount of weed a person gets per month, the minimum age.
Also, here in Brazil, the weed you buy at favela has a really bad quality, because the ""mafia"" presses the weed (
pressed weed ).
The process of pressing(in Brazil atleast) also adds conservants that worsens the quality of the weed.
IF it was legalized the weed that was going to be sold on coffee shops or drugstores idk would be good, I mean, really good and would be cheaper.
Here if you want to get pressed weed you can buy it for $0,41 a gram. If you want to get better stuff like skunk you have to pay around $28 a gram. I don't know how much it would be if it was legalized but it would be really cheaper.
Legalized Marijuana -> better quality; better prices; better regulation; less milicia; less drugdealing;
I don't know if your country is ready to be legalizd but mine is.