I don't understand this argument I keep hearing. What is your understanding of parenting that doesn't involve controlling what they are exposed to? It sounds like you want to say, parents should parent in any way that doesn't burden non-parents. Why would that be in a democracy?
This idea that parents should have to be the gatekeepers for everything doesn’t work.
We work better as a community, and we have democracy so we can elect people to take care of things that are good for all of us.
Broadly, as a society we have taken to blaming individuals for not being perfect at everything.
Parenting is traditionally a group activity. The individual consumer capitalist parent is a recent, mid 20th century onwards, construct.