Interesting post, thank you.
I’m not convinced that pigs in factory farms have lives that are worth living, though. My intuition runs in the opposite direction: because pigs are quite relatable, whenever I see their conditions, I see beings that are incredibly bored and incredibly frustrated (as can be seen with bar-biting and the tail-biting of other pigs, for instance), along with the physical pain and stress inflicted upon them during confinement, transportation and still, in many cases, slaughter.
As David Pearce has said, self-mutilation and mutilation of other members of the human species is only really observed in humans who emphatically don’t have lives worth living.
For me, I’d say the decision about which meat to eat would rest on my thoughts on the relative importance of the suffering I’ll be inflicting on the non-human animal(s) vs the suffering that will occur due to my impact on the climate by buying the meat. Unless one thinks that the suffering from both domains is very similar, the larger impact of one should be enough to tip the scales to either beef or chicken.
Personally, I think I’d eat beef.