Humans do not have the same metabolic paths as most apes, you cannot break down cellular walls and you don't create nutritionally significant amount of fatty acids in your intestines.
The fruits you eat are also rich in fructose since they are domesticated fruits this is in stark opposite to what "fruits" wild apes consume.
I'm not generalizing it for all apes because different apes have different diets and different metabolic paths chimps do not ferment cellulose in their colon but they do eat ripen fruit in which the fatty acids develop they also eat fruit which ferments on the ground, they also eat pith all of which is rich in lipids, when you discount the fiber in the chimp diet you will see that it's also nearly 50% lipids even when accounting for plant sources only and not them sucking the skulls of small monkeys for the juicy fatty acids that make up their brains (don't go looking for that, trust me this is something you cannot unsee...).
Human physiology is very different than that apes if we go back again to the gorilla then the small intestine and colon ratios are reversed in humans the small intestine is about 50% of the overall digestive tract in gorillas the colon is 50% that is because they get most of their nutrients from secondary fermentation where human physiology is centered nearly exclusively around absorbing available nutrients in the food hence why we also cook food and why eating raw vegan or raw anything is a terrible terrible idea.
Saying that our GIs are similar to apes is true but it's like saying that our muscular and skeletal systems are similar but the differences are still night and day. Our bodies are designed to consume ready to use nutrients and more importantly pre-processed nutrients (is suggest reading "Cooking as a biological trait") and to extract as much of them as possible in the shortest time as possible, we don't spend all our day eating and we don't eat 30-40kg of food a day even those of use that weight like a gorilla. Our GI is the gasoline engine while most apes are coal powered steam engines they both still use pistons and consume some form of hydrocarbons but put one in the other and the result will not be pretty.