What critical aspect did critics argue Jean Piaget failed to give sufficient consideration to while concentrating primarily on universal stages of cognitive development?

According to Jean Piaget's theory, which of the following best represents an example of assimilation?

As per Lev Vygotsky, 'inner speech':

'Cognitive development is viewed as a socially mediated process, in which children depend on assistance from family, peer groups, and other people for suitable intellectual development.' Who stated this?