Yet none of those far more problematic things comes with an age check, a fence, government controls or any special kinds of locks. We just educate children, and parents pay attention. Children that are too young to understand are put in special places like kindergarten, and even at a later age are often supervised by responsible adults.
I don't see why the internet should suddenly be all of that in reverse: Things like the online safety act require a whole world full of child-safe sites, and a child-impenetrable fence put around the few ones considered unsafe. This is totally ass-backwards.