Nice article. People vary (genetics / epigenetics / environment / microbiome etc) so it is natural that what works well for some, won't work so well for others. Just a matter of finding out what works for you - might be 70, 90, 100% plants and so on. And in terms of having a positive impact on animals, someone who is healthy and happy on 95% plants say, is going to be more beneficial than someone who is depressed and unhealthy on 100% as that example turns people away. Wouldn't be surprised if the optimal diet turns out to be mainly, but not exclusively, plant-based as that is how the five longest-lived and healthiest populations eat (the Blue Zones populations)