Buying meat in a store is not a question of moral, but directly asking someone to kill an animal for you, while you have something else to eat, is.
That's simply not true. These animals are being killed, because there is a market for it. Sure, if you, personally don't buy one package of dead animal, not much would change, but if you and many others with you decide to only buy plant-based alternatives, leaving the dead animal packages to rot, the store will buy less dead animals next time and will look for a bigger variety of plant-based alternatives. If less dead animals are being bought, less animals will get raised and murdered, because the market will simply shrink.
So yes, the choice of every single one of us is one of life and death. If our preferences change, the products being produced will change. It's all in the hands of the consumers.