We are slaughtering, maiming and torturing people (plants and animals) all of the time, non stop, since the beginning. We build ever more sophisticated machines to do it. I cant even look at the butcher robots that feed me.
Chimeras might actually improve the situation. It would force us to question our holier than thou, my shit don't stink attitude. I for one welcome our chimera underlings. It will be a revolution of philosophy.
Stopping supporting the animal-killing and animal-experimentation industries as far as you easily can, would improve the situation.
i.e. Stop eating "meat". And imagine the oceans without humans fishing them lifeless.
I'm not sure about the purpose of your comment, but it sounds like your conclusion is "therefore can do whatever we want to other species." As if ethics doesn't apply. As if we shouldn't try to minimize that hurt. Maybe I'm wrong about that.
Paragraph speculating about such arguments and why people use them:
Hopefully one day soon people aren't still offering "plant=animal" justifications of eating animals, like this. I find them very depressing. It's as if suffering is a joke to these people. Or something, I don't understand. Just repeating pro-meat arguments they've heard, I guess. Maybe it's a positive sign, and such comments try to bury unease from their growing sense of ethical responsibility to other species.