There's not enough funding, not enough social workers, not enough resources, not enough time. Lots and lots of paperwork, huge caseloads, massive pressures. You get slated for doing anything (bloody social workers stealing kids/ locking up mentally ill people on a whim) and slated for not doing anything (bloody social workers leaving children in danger/ not detaining a clearly unwell person). And yes, there are some awful social workers.
I don't work in CP, I can't do it, I do not have the emotional resilience for it. Lots of friends do, even my toughest, hard as nails friends live their lives in constant terror that today will be the day something is missed and one of the kids on their list dies or is seriously harmed. When things go well, it's not them who are praised, but when things go badly, it's them who are blamed. Not that they particularly want praise- they want smaller caseloads, more resources and services to refer families to, less paperwork, more time to get to know families and children properly, to know management has their backs, to do a good job.