It doesn’t change what you said but it does mean the argument is invalid.
It has always been easy peasy to get pot.
It was even easier to get than cigarettes and they weren’t terribly difficult to obtain.
However easy it was, and yes I was around in '73, it's easier now for minors, in states where marijuana is legal for adults.
Most of the supply chain now for minors is legal, in those locations. It's grown legally in those states, a middle man can legally buy it in those states...etc.
It simply stands to reason that when most most of the supply chain is legal for adults, it becomes easier to obtain for minors.