Most people are wrong! By any defensible ethical system, it's wrong to kill sentient beings when you don't have to. This goes double when it's terrible for the environment.
Of course the discussion should be around the conditions that livestock spend their time living in because animals obviously are "happier" when living in natural conditions, but as far as I am aware animals do not have any preference on when or how they die (as long as it is not painful and drawn out).
My question usually is: "Your interpretation of 'plant consciousness' and consciousness in general aside - do you personally see no difference between a flower and a cow?"
Or are you saying that what society deems ethical (regardless of what actually is, in fact, ethical) tends to align with actions that are good for people?
Our best guess is that plants do not experience suffering in the same way that animals do.