That's more an argument in semantics. Developmental psych actually has this as a brain development stage, with the later stages being about critical thinking even if the earlier phase doesn't seem so. Experiments were done where children of various ages were tested on benchmarks such as volume and kids under a certain age failed almost universally (I forget the age, something like 5 or 6) in the same way that infants lack object permanence. Later, at 9 and around 13 (?) the same framework argues that the brain gets basic and advanced problem solving and critical thinking, although even that theory admits plenty of people skip that last milestone.

Your point is more a common logical (sensory?) fallacy that plenty of adults fall into, but isn't necessarily the same thing. At least, I think it is, I'm a bit busy right now to check and it's bad enough I'm typing this out instead of taking care of my own toddler, lol.