This graph above shows the trend downward for meat consumption, despite the growth in the human population.
Billions of cattle, hogs, sheep, chickens, and turkeys are killed every year and turned into slabs of meat for human consumption. In recent decades, corporations have turned the meat business into a horror of efficiency and indifference to suffering. Cattle packed into feed lots, hogs into gigantic, stench-filled factory farms, chickens jammed into cages with their beaks cut off to prevent them from pecking each other to death. The public remains largely unaware of these horrid practices because of meat industry political lobbying and the media's complicity. In some states, they've even passed 'food disparagement' laws that can bring you big trouble for exposing the cruelty associated with factory farming.
Humans are omnivores. Eating meat comes naturally. But we also eat lots of fruit and vegetables. In fact, we can get along very nicely eating little or no meat. It takes about ten pounds of grain to produce one pound of meat. For humans, it makes a lot of sense to eat lower on the food chain, which means a plant based diet, eating fruits and veggies.
It's not just about saving animals from suffering an ignominious fate, though that is a very worthy reason to rejoice over declining meat consumption From a practical, economic viewpoint, it's just more efficient and better for the environment to eat lower on the food chain. Moreover, there's plenty of evidence that humans who eat little or no meat are just more healthy than their 'meat and potatoes' brethren.