Well because we are Apes and we did evolve into humans. The other apes have gone their own evolutionary way.
The mistake you’re making here, no offense intended, is that you are kind of placing the cart before the horse and confusing yourself on the biological taxonomy.
In biological taxonomy you have a classification system that starts at the top with Kingdom which contains all the groups of life forms followed by 9 sub groupings of life forms in which at the very bottom level is the species subcategory which is the basic unit of taxonomy and defined as a group of living organisms consisting of similar individuals that can interbreed.
The Great Apes is just a synonym for the taxonomic “Family” classification for the Hominidae Family. Which is four steps above the species classification in the taxonomic hierarchy. A taxonomic family is made up of groups of species in which the species groups have widely similar homologies (similar or the same anatomical structures). Human beings (aka Homo Sapiens or modern humans) belong to the Hominidae or Great Apes Family. That is to say Humans are Great Apes. So are Gorillas, Chimpanzees, Bonobos and Orangutans, etc,.
However all these species are distinct and separate species that cannot interbreed. Because the other Great Apes species cannot interbreed with each other there is no evolutionary pathway for Homo Sapiens to have evolved from the other great apes. Evolutionary theory would not predict this happening but what it does predict is that due to their great number of homologies that somewhere back in time all the Great Apes species shared a common ancestor.
I hope this explains for you why humans have not evolved from other Great Apes.