That source is awful lmao

Think of a human being who does not take vitamins. As long as the person eats and drinks, he will stay alive. But without vitamins he will be weak and susceptible to ailments. That person will have a hard time recovering from sickness.

In reality, Venus flytraps require occasional insects in order to flourish. They’re unable to absorb the nutrients insects provide any other way, because they evolved in nutrient-poor soil and their roots cannot tolerate soil nutrients. Similar systems of insect nutrient absorption have evolved independently many times, e.g. multiple pitcher plants, sundews, and bromeliads