Zoos have helped people and animals in many ways. Although it is “cruel” to the animals, I think zoos are necessary.
Firstly, zoos can get endangered animals into breeding programs and help them reproduce and breed. Some zoos have a breeding program and can save endangered animals from extinction. Here are some that we've saved; orangutans, polar bears, pandas, white tigers, kiwis, narwhale and so many others. By putting the animals into the breeding program the animals can breed in peace and security and predators cannot get them.
Secondly, they should be kept because since the time when zoos were cruel, tiny and so unlike their old homes, zoos have got much better and are more like there wild habitat. So if you think animals should not be kept in zoos because of how small the enclosures are, your reason is weak.
Finally, zoos help people to learn about the different animals including how, when and where they hunt, breed and sleep. They have learned all about where the great white sharks migrate from south Africa to Australia. How butterflies migrate from Canada to Mexico. How jelly fish migrate from one side of a tropical lake to the other. All of this is done, helped by or supported by zoos.
Would you like to live in a world without many animals? Well the knowledge gained and the animals saved by zoos is extraordinary, I think zoos should be kept.