“Regulated, or prohibited? Those that want to use manufactured drugs are also not swayed by a law”
No they are not. No law stops everything. Prohibiting those ingredients arent possible because they have legal applications. But the stuff needed to make Meth and these other manufactured illegal drugs cant just be bought from the local grocery or garden center and mixed together. 99% of the time the stuff in it is made by only a few companies, and has to be driven over state lines. Much easier a target for the DEA to have their “war” on.
"Easier" is a relative term - the War On Manufactured Drugs appears to be failing. But I do agree that ending the War On Disapproved Plants would leave the other war that much less unwinnable.