See above, my question is how do you know developmental delay is no reason for CPS to get involved.
When school staff sees developmental delays, they refer students for testing for said specific delays. That could be hearing, vision, dyslexia, attention deficit, autism spectrum, etc. When they see signs of possible home neglect or abuse that may be *contributing to* said delays, they report the specific neglect or abuse signs to cps. Things such as malnutrition, signs of beatings like bruises, burns, & welts, mites or other signs of filth in clothing, consistent lack of sleep, smell of alcohol or drugs, refusal to comply with remedial interventions, consistent truancy w/o acceptable reason, lack of lunches or money for lunches, signs of sexual abuse, uncontrolled urination or defecation, and so many more symptoms are taught to all teachers and those in positions of required reporting. No child is EVER reported to cps for a simple developmental delay nor would cps involve themselves in developmental delays without reported sign of abuse or neglect. An example would be delayed eye-ear-hand coordination in early elementary. This would never be reported to cps. Consistent lack of sleep, unexplained bruising, hunger, smelly urine soaked clothes daily, smell of meth cooking chemicals, and starvation level skin and bones ALONG with lack of appropriate eye-ear-hand coordination would be referred to BOTH cps and for school adjacent professional analysis and remediation. These two entities do not overlap other than for reporting purposes for the highest good of the child and in the best interests of the child's health, wellbeing, and future.
This was a long explanation but I worked professionally as a social worker, a teacher specializing in at risk populations, and as a juvenile justice professional. I've definitely seen a *lot* of tragic developmental delays caused by neglect and abuse, along with plenty of adults who simply shrugged off said abuse and neglect as acceptable. Its not just the victim children that pay, it's society as a whole.
ETA: a reading delay is diagnosed & remediated by *school* intervention. Abuse and neglect are remediated by *cps* intervention. Its actually very simple.