While this is true, it’s also not the whole truth. A did a fair bit of literature review a while ago, and my memory is that the green parts of immature fruits and berries do contribute a bit to photosynthesis, but only contribute a small portion of the sugars in the fruit. In part this is because they have many fewer stomata, and also because their shape is not optimized for photosynthesis.
The majority of the sugars in fruit come from the leaves of the plant.
