It's about being effectively illegal or illegal 'enough'. If there is a good chance you will get a CPS call for your kids 'welfare' due to not being 'supervised', even if nothing happens, is plenty enough for most parents to not let their children be unsupervised no more. Most CPS visits have a background threat of 'we will take away your children', and that is plenty enough of a threat as it is.
Then the chilling effect starts and people just never bother because they read or heard of that happening once somewhere.
In a world where CPS can’t even take kids away from parents whose car catches on fire with their kids in it while they are shoplifting at a Walmart for a few hours, I don’t really see this as effectively chilling.
It is chilling. And beyond kids being taken away, being forced to go to parenting classes or just having to be there for follow up visits, having to pay layer are all significant hurdles.
In the case you mention, kids would be supposedly taken away for being without supervision in the car. Shoplifting is unrelated crime.
The adults left the kids in the car to go shoplifting for hours. But more to the point: you think CPS is way more effective (let alone over effective) than it actually is. The few anecdotes to back that up have always concluded in favorable outcomes to the parents.
Then the chilling effect starts and people just never bother because they read or heard of that happening once somewhere.