Most increase in land-based agricultural productivity in this day and age comes from intensification on existing land or removal of forested habitats. Those come at a huge cost to biodiversity and ecosystem services. They also have social costs to other humans.
> "Surely you can figure out how eating beans is a little more kind." I don't think this snarkiness is very productive, but I'm super used to hearing this sentiment; often the people who express this type of idea have really good intentions that I am totally aligned with, but they also fall into logical fallacies usually due to missing information around ecology, agriculture, and food systems. It makes perfect sense if you take a very narrow view of how food is produced and what alternatives there are for land and water use: just eat a bean because it doesn't scream! Totally. But growing that bean comes at a cost and ignoring that because you read Sinclair or can afford to shop for high-end foods isn't helpful. I think it is a fantasy to suggest that the problems will be solved if peoples and cultures around the world just subscribe to my view of what is ethical or desirable.
Any fish would prefer you eat a bean. But the animals and plants that would use the land on which its grown would prefer you eat a fish. Those of us working to build sustainable food systems that minimize the overall impact on natural systems, biodiversity, and ecosystem services will fail if we take such a simplistic and naive view of the tradeoffs.