However, you gotta find ethical agents and that can be a challenge.
True - But that's “only” a very limited protection. See the “child actor” horror story comes AFTER the movie is over and they/their parents/their agents/their fiends (er, friends) are SPENDING the money earned on set.
After the movie is over there ain't no protection for these children except morality. And there ain't been no morality in Hollywood since 1910.
If you read my subsequent post, you’ll find that the money gets put away until the kid reaches age of majority. Unfortunately, if the kid spends stupid at that point, not much can be done about that.