I agree with the idea that we haven't had a rational conversation about cannabis due to the government's "reefer madness" madness. But I also think saying "I don't know a single person advocating to make it available for children for recreational use" is a strawman. You don't need to advocate for children to use it, but I think a lot of people felt (I feel like this sense "peaked" in the early stages of legalization) that pot is essentially harmless. That is, that it may not be great to binge on it, but a lot of people thought there were little, if any, long term negative effects. That general belief certainly filters down to young people.

My understanding of the most recent research is that weed is especially harmful when it comes to long term brain development for adolescents (and, ironically, that it can, though research is definitely not conclusive, have protective cognitive benefits for people who don't start weed until their brain is fully developed).