Human is dependent on plants for his nutritional requirements. If he starts eating only meat for the entire life, Can we say that he is no longer dependent on plants for survival?
Animals get nourishment from plants. So he is indirectly dependant on plants.
Photosynthesis is responsible for producing food in plants. Herbivores obtain food from plants. These are then eaten by carnivores. So even if we eat only meat, we will be indirectly dependent on plants for our nutritional requirements.