Probability of charges vs. Traumatizing a child by asking them to testify

My child recently disclosed sexual assault by an older child (13). It happened once, but we have since discovered this child has inappropriately touched other children as well and several parents have also now made reports.

We've been told by the sexual assault unit in our town that unless one or more parents press for charges that there will be absolutely no police involvement, warning, sanctions on being around young children, or repercussions of any kind for the assaulter.

We were told that the process is that the assaulted children will be interviewed by child-interview trained detectives, alone without parents present, but video-recorded.

Then, if anyone proceeds with pressing charges they will involve the assaulter. If the assaulter does not confess, then the case moves to court where the videoed interviews will be played but the children (4 years old) may be asked questions.

This seems absolutely insane to me. These children are 4 years old, have no basis to fabricate the information they gave from, and aren’t capable of understanding the seriousness of what’s happened to them.

They are going about their lives as normal, and all parents are dealing with victim services to ensure that they are cared for properly. To have them be questioned by police separate from their parents and then potentially cross-examined by the crown in court is nauseating to me. It does not feel protective and feels like it runs the risk of further traumatizing them. And for the alternative to be just absolutely NOTHING?! is incomprehensible. Where is the protection for vulnerable children?!

Has anyone been through this process or have any advice???