There's a cuppla reasons these policies are in place and will problee remain so.

The US has treaties with numerous countries claiming they'll never legalize these drugs and will pursue trafficers jointly. To legalize these drugs they'd have to violate these treaties which in all truth just isn't likely to happen.

With government always standing at the ready to control their citizenry the vilification of drug users makes for an easy target and allows the govt. to keep a thumb firmly placed over society as the drug enforcement operations themselves allow for societal infiltration and surveillance on a broad scale, which I think govt. likes too much to willingly give up.

Sadly our justice system is bogged down by a huge backlog of drug related cases, our prison system is overburdened with drug related convicted criminals and the state and federal governments spend untold billions annually collectively in attempting to "win" this obviously unwinnable war