You can survive on just fruit if the fruit is all you have to eat.
Fruit is very healthy for you and provides your body with energy, vitamins, minerals and even nutrients.
The fruits also contain antioxidants as well which are very healthy for you and helps improve your kidney health and liver health.
However if you have more food than just fruit then you should eat other foods such as potatoes, salads, meats etc if you're a meat eater and not a vegetarian.
But if all you have to survive on is fruit then you can certainly survive on nothing but fruit but your health will be much better when you eat a variety of different foods.
I love lots of fruits and snack on apples, bananas, pears, grapes etc.
But I also love to eat other foods such as vegetables, and some meats such as bacon, hamburger, chicken etc.