In the U.S., there are laws like the Coogan Law, but they mostly focus on protecting child actors' money, not their safety. There aren’t strong national laws to prevent abuse or require studios to have child safety officers. Because of this, abusers can stay in the industry and continue working around kids.
In many American productions, child actors don’t have emotional or mental health support on set. They might not have someone to talk to if something feels wrong. Without trusted adults or advocates, many kids stay silent about the abuse they face.
There are usually rules about working hours, but not always about who is watching the kids during filming. Some adults on set are not trained to protect children, and background checks aren’t always required. This makes it easier for abuse to happen without being noticed.