With so much talk over evolution and natural selection, it's interesting to examine more closely what Darwin and Alfred Wallace (a co-discoverer of natural selection) actually said on the issue.

Historians of science have noted that while Darwin considered the ideas in Wallace's paper to be essentially the same as his own, there were important differences. Darwin emphasized competition between individuals of the same species to survive and reproduce, whereas Wallace emphasized ecological pressure on varieties and species forcing them to become adapted to their local environment or become extinct. It has been suggested that Wallace's emphasis on the importance of adaptation to the environment for survival and Darwin's emphasis on competition between individuals of the same species was at the root of their disagreement over the importance of sexual selection.

Others have noted that another difference was that Wallace appeared to have envisioned natural selection as a kind of feedback mechanism keeping species and varieties adapted to their environment. They point to a largely overlooked passage of Wallace's famous 1858 paper:

The action of this principle is exactly like that of the centrifugal governor of the steam engine, which checks and corrects any irregularities almost before they become evident; and in like manner no unbalanced deficiency in the animal kingdom can ever reach any conspicuous magnitude, because it would make itself felt at the very first step, by rendering existence difficult and extinction almost sure soon to follow.

The cybernetician and anthropologist Gregory Bateson would observe in the 1970s that though seeing it only as an illustration, Wallace had "probably said the most powerful thing that’d been said in the 19th Century". Bateson revisited the topic in his 1979 book Mind and Nature: A Necessary Unity, and other scholars have continued to explore the connection between natural selection and systems theory.

In other words, instead of thinking that natural selection is only about competition between other people for sexual selection, like Darwin did, it would be more instructive to think about natural selection as adaptation to a complex, dynamic environment (that includes other people), like Wallace did.

I think the both approaches are of first approximation level.

It seems to me that Darwin and Wallace may have been talking past one another (something very common). To compete with other members of a species for mates takes into account that the competition is in the real world. The fitness of one's adaptation to that world is a factor in competing for mates. Darwin and Wallace seem to be both saying the same thing but in different ways.

Big Tits and Competition of the Species.
Fools and weak can survive better, all depends on environment we create around.