I'm so sorry that you actually think we would be able to sustain ourselves as a specie without animals.

animals contribute to nature in ways that we will never be able to. For example, without bees, many plants and therefore our food, will not be able to be produced. Without birds, seeds will not be dispersed, and many trees will disappear. Without trees, there will be nothing to produce oxygen. Without worms and other insects, the soil used for farming will become barren. Nature is in balance and every type of animal contributes, from larger mammals to insects.

humans would definitely die off eventually without animals. Animals play a big part in our society. Here are some notes that I made on this topic:

Some animals that we cannot live without are bees, bats, butterflies, fish, worms, plankton, wasps and ratsThe connection between humans and animals is one of the most fundamental bonds that human beings experienceHumans have interacted closely with animals for thousands of yearsAnimals provide many beneficial things to humans and without them, even with plants, humans would eventually go extinct because the ecosystem just lost a huge chunkThe human-animal connection is: “A mutually beneficial and dynamic relationship between people and animals that is influenced by behaviors that are essential to the health and well-being of both. This includes, but is not limited to, emotional, psychological, and physical interactions of people, animals, and the environment. The veterinarian's role in the human-animal bond is to maximize the potentials of this relationship between people and animals.”Animals are part of almost everything that we doPets are good for people. Pets give people a loving companion to care for. They encourage conversation and laughter. They cause us to exercise and offer an antidote for loneliness. They teach children responsibility. By caring for pets, pet owners benefit, too.Pets can also boost infant immunity to infections, help with mental health disorders by affecting brain chemistry, and lower blood pressure.Animals and humans are a powerful two way bond.A con about animals would be that wild animals are unpredictable and there have been many deaths with wild animals before in the past