So whether or not you're vegetarian or vegan, cutting down on your meat intake is a good idea for various reasons – high among them being environmental concerns and overuse of antibiotics on farms. It would be foolish to think otherwise.
The thing is, some cultures have been using meat substitutes in food for centuries. Either for religious reasons, like some schools of Buddhism, or among people who don't always have access to meat. So it can be worth following their example.
Humans are not evolved to be herbivores, and I really don't like all the people who say "go vegan" without also telling people exactly what that means. So in case anyone finds it useful, here's a little thread about meat substitutes to include in your diet, and nutrients to make sure you're getting enough of!