I think that they are good and bad. It is good to experience animals so close, but it's bad to keep them captive. So, my opinion is to just watch animal videos by National Geographic or something like that. As long as the animals in zoos are not treated badly, which no one knows if they are, the zoos are a good place to let an animal live. As long as we have zoos right now, we should try to make them cleaner and better for the animals and let the public enjoy the animals while they are there.
Zoos are a good place for endangered species so they can multiply.
But hopefully, even cages allow some people to see animals they may never see, and therefore develop a sense of of ownership for that animal's well-being and the desire to see it in sufficient numbers and in a natural habitat. It is also great for children's education to have a better understanding of the animal kingdom. It depends really. Say, if you put a cheetah in the zoo with half an acre of land, it would be better off in the wild. So with proper care, yes.