If there is a problem, the regulation may be changed, and additional measures taken to get rid of it.
The main issue with these laws is that they are speculative. It is actually very likely that nothing would change much if at all, except number of arrests and related costs. Oh and reduced cut for the black market.
Psychedelics have been available and used throughout history with few problems in ritual settings. (As opposed to drugs like opium, tobacco or alcohol which have always been one with few exceptions yet are less regulated.)
"Think of the children" is a cheap shot that can be used to set any number of odious laws. Show evidence of harm and how the law helps with it.
The real reason psychedelics were banned in the US is to have a reason to jail politically inconvenient people in Vietnam era and bunch of the world has followed the leader.