But stupidity is relative and stupid children are more common. The heuristic can be reworded as adult parents are more knowledgeable and capable than children.

Put the average child in the position of the average parent and you will see the difference.

"Children" aren't a homogenous group. Neither are "parents." And "stupid" is not a single metric.

Pre-teens don't have practical adult skills and have poor or non-existent emotional regulation. Teens have some adult skills, are learning or experimenting with others, and have patchy self-regulation.

So it makes perfect sense not to allow kids to do things that are dangerous to others, and to limit what teens can do with strong guide rails.

But when it comes to world view and insight, teens can certainly be wiser than their parents. They may not know what to do with their insight, but they're not wrong - just inexperienced.

Meanwhile many adults are hopelessly naive and may be actively self-harming, especially politically and culturally. And when adults have addiction and/or Cluster B issues, even fairly young kids are more likely to be reliable and responsible.

>They may not know what to do with their insight, but they're not wrong - just inexperienced.

taking insights from teenagers...really? Do you know what kind of "insights" I had in my teenage years? They are downright cringe.

> The heuristic can be reworded as adult parents are more knowledgeable and capable than children.

I think that's true in general, but when it comes to making decisions about the child I think that has to be weighted against another heuristic that's often but not always true: that people know what's best for themselves better than other people do. I think people often wrongly neglect that principle when it comes to children assuming that they don't know what they're talking about without taking the time to listen and understand their point.