Anyway the synthetic drugs are more profitable.
The cartels have good chemists capable of synthesizing fentanyl.
The fentanyl is more powerful and they don't need to wait for the poppies or the coca plants and easly contraband it to USA.
There will always be a black market for drugs no matter how many you legalize. You think Fentanly is powerful? No one can fathom what is going to be introduced over the next 10 years , which includes pot. Get ready because its only going to get more hardcore.
