This is the argument that I used when I was an adolescent who thought himself very wise and smart but in reality just wanted an excuse to not have to change the lifestyle that I was comfortable with.

Saying "life only comes from death" is a cowardly reductionism. It creates a false equivalence between plant and animal life that lets you ignore the fact that sustaining human life does not require the wanton suffering of animals. And it certainly doesn't require animals to be suffering at such massive scales and in such cruel ways.

You're probably someone who will cite studies which indicate that plants emit distress signals when they take physical damage, and you'll argue that therefore plants suffer the same as animals. But that's an intellectually dishonest argument. Suffering as we understand it is more than just a chemical reaction to stimulus; it emerges from an awareness of being alive and an instinctual desire to remain alive and unharmed. Plants do not have that kind of awareness.

There are predators in nature that only know how to hunt to survive. Their digestive systems are specialized to consume the bodies of other smaller animals. And their ecosystems depend on those predators to balance out the reproductive cycles of their prey, otherwise the prey animals would become overpopulated and wipe out life forms lower on the food chain.

The fact of the matter is that humans have not been a collaborative member of any ecosystem for tens of thousands of years. We cause massive harm to every ecosystem that we're a part of, and the mass slaughter of farm animals is the worst thing we've done to this planet yet, even more harmful overall than CO2 emissions. We're eroding the soil and using up the fresh water in ways we can't sustain, and then to top it all off we're inflicting the largest scale unnecessary suffering in the history of this planet. And all of it is being done so that humans can enjoy a pleasure that is both unnecessary and easily replaced with a small amount of agricultural and supply chain reform.

Humans are omnivores and the simple reality is that as an omnivore with options at your disposal you have a choice about whether the process of sustaining your life involves wanton suffering at a massive scale or not. If you think the suffering of animals is worth the pleasure you derive from eating their flesh then just be honest and say so. Don't be a coward like I used to be by pretending that animals and plants are the same.