On some level I think the answer is always the same, regardless of the headwinds or tailwinds: you do what you can with your limited resources to improve the world as much as you can. In some sense I think slowing the growth of factory farming in a world where it was growing is the same as a world where it is stagnant and we reduce the number of animals raised. In both worlds there’s a reduction in suffering. I wrote a creative piece on this exact topic here if that is at all appealing.
I also think on the front of factory farming we focus too much on the entire problem, and not enough on how good the wins are in and of themselves.
Hmm I’m not sure if I have a very considered answer to this question, except for the main argument that I think it’s much harder for people to see animals as having rights/moral value since they look different, are different species, and often act in foreign ways that make us more likely to discount their capacity to feel and think (e.g. fish don’t talk, scream, or visibly emote).