It’s pretty clear that humans haven’t eaten a primarily fruit based diet in a very long time. It’s likely that moving away from that diet predated changes that made us human.
you could certainly make the argument that most humans haven't a primarily fruit based diet for a while (although evolutionarily it really hasn't been that long) but that doesn't change the fact they are our closest ancestors and the way our bodies are built STILL very much mirror those of primates which means they, in many ways, still work as theirs did. It's not like we have evolved entirely different digestive systems or something. Essentially everything is the same (which again makes sense as evolution is a VERY slow process)
Gorillas digestion is based primarily on fermentation of plant fiber, which is why they have a huge gut. Humans have an acidic stomach environment which doesn’t digest fiber at all. A small amount of fermentation happens in the human gut, but it can only produce a few calories a day.
Evolution has changed us considerably in the last couple million years.
We may be closely related genetically to gorillas, but our digestion is probably closer now to a dog’s than a gorilla’s.
It’s pretty clear that humans haven’t eaten a primarily fruit based diet in a very long time. It’s likely that moving away from that diet predated changes that made us human.