They just leave them outside in the stroller in someplace like Sweden. It's hilarious how on HN the nordic countries are idolized and leaving strollers outside while the kid stares at the street man smoking fentanyl out of a piece of aluminum foil indicates you are a glorious liberated member of intelligentsia but by god if you put a tablet on to get a moment of peace while you take a shower then you are a hideous sub-human piece of garbage.
Babies. They leave there babies. They do not leave there two years old already fully capable to toddle away and still dumb enough to walk into anything.
Also, not every city has the same massive drug addiction homelessness problem as yours.
In most countries it's illegal to leave any child unattended in a way that puts them at risk which is a vague definition. But if something were to happen to the child while unsupervised any vagueness collapses into negligence. A baby will sleep in the pram, but for a toddler to be abandoned alone strapped in the pram is capital punishment.