“Since the outset, Allbirds has been clear that consumers do not buy their shoes because they are sustainable,” said Ken Pucker, professor of practice with the Tufts Fletcher School. “Instead, they seek to make the most comfortable, simple and purposeful products that happen to be lower in carbon.”
https://trellis.net/article/allbirds-wants-footwear-companies-to-copy-net-zero-shoe-design/