His buddies coax him into trying a “hit”. Where he would have reservations while the “hit” was illegal, and he might lose all he has due to a possession charge. That threat of charge is no longer there, freeing up the temptation to use.
The grave intrinsic harms remain. To repeat: Is the illegality of heroin or meth YOUR primary reason for not using them? It's way down on my list.
Of course not. Take away the
criminality and more will try
abusing whatever activity they
weren’t allowed to do before.
All drug abusers started somewhere,
doing away with possession laws
will just make it easier to get
started.