This reminded of a CK Lewis bit about how modern humans deploy a lot of resources trying to save "weak" babies, and thus undoing evolution's natural selection process.
Darwin's theory of evolution and natural selection were never really about directly competing against other members of their species. There was certainly a component of that but natural selection is predominantly about competing against nature itself.
It's all about developing traits that help a given individual or community/ecosystem survive and thrive. And unsurprisingly in most ecosystems it's not competition from peers but rather competing against weather, environmental conditions, and the food chain/predators. So what you see is that at basically every single level (from plants and microbes, up through insects, birds, mammals, and at all stages of human history) you have a constant push for mutualistic behaviors.
It's why birds warn their entire ecosystem (including other bird species and non-bird species) about predators and danger. Or as another bird example, migratory birds will cooperate and share food even when migrating with birds of different species. Anything that can bolster the ability to survive and thrive for the community as a whole (and often entire ecosystem) ends up driving evolution far more than advantages for a single individual. Doubly so with punishing adversarial advantages for individual that end up disproportionately harming the community/whole.
And the competing against nature itself you mention, is often determined by the territory a group is able to claim. Some places get drought, others freeze, and in others food is plentiful. Nature may not be a free-for-all deathmatch, but it's not a pacifist coop either. At least, most species don't behave that way.
And because of that, territoriality tends to be fairly low in most species until the food supply becomes constrained. And even then it's a gradient where hostilities generally only escalate out of desperation rather than innate competition. i.e. Competing between individuals or communities tends to occur mainly when they fail to compete against the environment and run out of other options.
But really my point was just about the general sentiment that it's "against evolution" or "against natural selection" to help the weak and that doing so is something that humans do out of a unique sense of love or kindness or whatever.
If killing the unfit is the way to go, you should kill your babies until they become immortal.
Natural selection has always been about reproduction.
However, the big story in the west is that most sexual congress does not produce babies anymore.