I think you are misunderstanding my question.
Let's say we abolished it. What situations would arise that our existing legal system couldn't handle?
The big issue that I can see is placing children whose parents have been arrested or have died into new temporary or permanent homes. I am open to discussion of the best way to handle that.
But what else? What other functions must be replaced, that can't already be handled by the existing legal system?
I arrest you and you have a child with you and no one else is there. What should I do with the child? Do I just find someone to take it? Who takes the time to make sure the child is getting placed with actual family, that the child is being placed in a safe environment? I can tell you that we are not equipped to do that. We don't have enough people to answer the calls on the radio let alone pull an officer/officers to sit with the child, track down family, and vetting them.