If you're a gazelle, or a lion, maybe. If you're human, you've benefited from millennia of cooperative work invested by your predecessors and peers.

That's an ideology, not a fact. There is lots of evidence of cooperation, symbiosis, and eusocial behavior, all of which differ from pure competition and complicate things. Nature can be very competitive, but a lot of the time it's also lazy and harmonious and prefers slack over maxing out efficiency.