Exactly! What other incentive does nature provide for all living things to evolve? Humans have reached the pinnacle of sapience and, as a result, have a comprehensive understanding of the world and universe.
Evolution is an axiom. Therefore, humans feel the need to identify a purpose for their existence. People define the meaning of life by cultural practices and customs and arbitrary inclinations based on how they perceive the world.
It's like an existential infection that we're born into.
If one human motivation best describes our species, it is the acquisition of resources, the only tangible assets required for survival and to foster a meaningless evolution in the vastness of the cosmos.