Kids tend to put back books that are age inappropriate for them, or ask the adults in their lives for context and guidance if they accidentally read a sex scene/violent or confusing thing. Source: me. There is no justification for a ban. Just talk to your kids and pay attention to their interests and give them content warnings and information they need to understand things they read. The government or another authority telling people what books they can and cannot read is VASTLY different from a parent saying to their own child, hey kid, you might wait a few years to read that one. Try this [pg book] instead.