Or, to put it more bluntly: you can't prove that eating animals (or gay sex, for that matter) are the "wrong" choices to make, no matter how much philosophy you've read or argued about. You can't even prove you exist or that this is reality. If you can't even prove that, you're a long way from proving that killing animals is a moral choice.
Analytic philosophy basically contends that if we assume axioms hold (correspond to the world in some sense) and we construct arguments from those premises which conform to logical rules, then the conclusions of those arguments are also true of the world in some sense. This is, of course, doubtable in various ways - but you pretty much have to abandon reason itself as the alternative.
Plants are sentient creatures
However, even considering the hypothetical that plants are sentient, eating plants actually causes the least harm seeing as livestock are not very efficient converters of plants to meat.
False:
https://en.m.wikipedia.org/wiki/Plant_perception_(physiology...
https://asknature.org/strategy/leaves-signal-presence-of-pre...
>eating plants actually causes the least harm seeing as livestock are not very efficient converters of plants to meat.
Let's continue this facile logic to it's conclusion: if animals are causing so much "harm", why shouldn't we kill them to prevent them from "harming" so much?