What is good and bad about zoos?

well sometime i think Zoos are good so that people can explore the different types of animals, because people know about snakes right but they might not know all the different types, but its also bad because animals in the zoo have a right to live their life in the wild and in their habbitat. but i think that because global warming is happening and polar bears are going to be extinced so they should take any remaining Polar bears now and take care of them in a zoo but i really don't know hope this has helped (it might sound a bit confusing lol)