For one it has been shown that all of Piaget's research was done on higher economic class children. Since he did not do his research on children with different economic backgrounds he can not for sure say all children develop this certain way. Children also tend to mature at different ages depending on there environment and what they are accustomed to. Lastly, children often prove to be smarter than what we perceive them to be. So it is hard to say that they can not logically understand things until they are close to a certain age. All these are key points in the beginning of Kendra Cherry's article "Support and Criticism of Piaget's Stage Theory" https://www.verywell.com/support-and-criticism-of-piagets-stage-theory-2795460
After doing my research I personally believe Piaget's theory make sense. Now while I do see some flaws I believe he has some key points in his stages and overall his theory on children's development is