The thing is, there is no necessary nutrient that you get only from fruits. Veggies blow fruits out of the water in every way except one - Sugar content. What I mean to say is that for every fruit you eat, there is always a vegetable that has the same nutrients in a higher quantity with A LOT less sugar. That's basically all fruits are... really sugary vegetables.
But you're right, our bodies all react differently, and what works for some may not work for others.