In a question about the low protein content in fruits, one answer suggests the energy, carbohydrate, and protein content in a fruit evolved to entice animal seed dispersers, not foster the sprouting seed.
Another answer suggests plants are made mostly of cellulose, hence why the fruit has more carbohydrates than protein. The implication here is that the content of the fruit is optimized for the benefit of the sprouting seed, which is constructing a plant, not an animal.
Both of the answers to this other question: Plant a whole fruit or only seeds? suggest fruit is all about dispersal.
Which is the correct explanation?
It seems like it would be an easy answer to prove experimentally: plant two seeds in nutrient-poor soil, one with its fruit whole, another with its fruit mostly eaten (or even entirely passed through an animal's digestive tract). Then see which seeds thrive better.
Obviously fruits cultivated for human consumption have had their evolutionary course commandeered for benefit of the frugivore. And to a lesser extent probably many plants have a symbiotic relationship with their seed dispersers. But is that relationship an enhancement of the primary evolutionary purpose, or an suppression?