The amount of grooming/sexual abuse in public schools has always been greater in both raw numbers and as a percent than abuse by not just Catholic Priests, but with Christian religious officials in general. It's also just as systematically covered up by a large institution (in this case the Teachers Union) as it was by the Catholic Church.
The reason you think otherwise is quite simple: the media helps cover up the abuse by teachers, while amplifying the abuse by Priests. Why? Again, simple: the Teacher's Unions are fellow ideological travelers with the Media, whereas the Catholic Church generally stands opposed to the most sacred cows of the Progressive Media. Note: this is not consciously nefarious or conspiracy, this has to do with how people tend to think about people on "their side" vs "the other side". For the media abusive teachers are not examples of systemic abuse and cover up, but rather, isolated incidents of bad actors and the Teacher's Union covering for them is just the Teacher's Union holding to their contract as a Union. Meanwhile for abusive clergy, it's an example of how the "other side" is systematically corrupt and has issues and is evil, and how the institutions there covering for them are enabling that abuse.