Ethical
We share this planet with an abundance of other sentient beings. Conservative estimates project that 56 billion farmed animals are killed every year. This number doesn't include other land animals, sea animals, or animals used in lab testing.
The animal product industry is incredibly cruel. Compound this with the environmental toll animal products place on the planet, and you'll discover that not using other sentient beings for commodities is kind not only to them, but to all life on our shared home.
It takes 10 to 15 pounds of plant-based food to produce 1 pound of animal-based food. Eating animals isn't only unsustainable; it's also impractical in a world where many humans go hungry every day.