"Aladdin is learning worldliness"
Now Aladdin has found out that there are also deceptions in the world, on whom a person trusts, he deceives. All this was necessary to be told in the story because Aladdin has to know the truth of the world. Because as far as we have seen in the story, Aladdin trusts everyone very easily, but now Aladdin has realized that not everyone is trustworthy.
Aladdin is a good person, he knows the sufferings and problems of others because he has also gone through the same. Perhaps that is why he is helping others because he has not forgotten his time when he was poor۔