Duty to report laws aren’t what you think, and they’re not always good. Everyone CAN report. Duty to report makes it illegal for them not to.

Let’s say a kid shows up to school with a bruise, the teacher asks how did you get that. The kid trusts the teacher and answers “my parents hurt me when I don’t behave”. If the teacher is mandated to report an inquiry is started immediately, but since it’s only one bruise and kids get hurt all the time, the parents get away with it. Now the kid gets abused even more for telling the teacher, and the kid realises that telling the teacher the truth will only make more problems. Next time it happens he tells the teacher “I fell”

If the teacher is able to exercise discretion, they can accumulate evidence until the odds of success are worth breaking the kids trust for their own interest.

Now doctors and nurses are less likely to have a long term relationship with children and having a duty to report means they don’t have to listen to excuses and can just shrug and say “I’m sorry, I’m mandated to report these types of injuries” so they can actually be helped by these laws.

Child abuse is a very delicate situation and easy answers are few and far between.