There are concepts such as Coup de Grâce, euthanasia or probably stuff in the context of suicide where people might argue for death over prolonged suffering. Though even there this topic is already controversial.
But killing a completely healthy individual without their consent or even AGAINST their explicit will based on the off chance of something worse happening is probably even more controversial.
Also for a start speaking of "prey animals" pretty much treats another individual as a means to an end and not as an end in itself. You linguistically argue that the other being's only purpose for existing is to be hunted and they might respectfully disagree with you on that one.
Like consider the other party in this, assume there's an apex predator hunting humans, making you a "prey animal". Would you want to be put down in advance or live your life until it happens or maybe even take your slim chance if an encounter happens? Also given that you could be hunted beginning at birth itself when would you wanted to be put down if you would? As an adult, a child, abortion, anti-natalism?
The whole premise rests upon life being suffering and negative, but for the respective individual life is what you make out of it and often enough people and maybe also animals can adapt to pretty much anything that isn't instantly killing them.
Also how is anything that kills you win-win for you? You'd be dead, there's nothing you have won from that. Life is a game that is lost upon death, so any death is death, is loss. Now again there are situations where the question arises if keeping on playing is worth it, but that is a question for the individual themselves, not for an observer and not without their consent.
Does human intervention with the ecosystem alter some sort of "natural evolution". E.g. fishing small fish manipulates the evolution of small fish. By fishing humans may alter the evolution of small fish so that they cannot thrive in their natural habitat.
There is no "natural evolution" in the sense of a predetermined plan that is "supposed to happen". Shit happens. And it happens how it happens when it happens. But sure any interference with anything can have consequences. Like certain species might roam in swarms to protect each other from predators, thus making them look bigger, more intimidating or simply confuse a predator by moving seemingly erratic or as a meta-being, because the predator can't focus on a single individual or conversely has to focus on a single individual and thus the rest can go on uninterrupted.
So that the violent death is a statistical sacrifice that if it doesn't happen there, happens elsewhere. Also if humans thin out the swarm the whole strategy might collapse and the species might go extinct due to being more vulnerable to their natural predators. Or humans might be considered the new natural predator (as they protect them from natural predators but are the source of their death) so over time the species might adapt to the new ecosystem and develop symbiotic or anti-human abilities.
