Animals should not have to suffer for the liking of humans. These habitats should be at least the size of two rugby fields so animals could have the freedom they need including proper food, water and environment which would mean they could live the way that they want.
Secondly, animals could hunt for their own food, look for their own mate, keep fit, wouldn't get bored, live a short, happy life instead of a long, lonely, boring life with the zoo keepers controlling every move that they do.
Third these enclosures would be far away from human pollution or destruction like huge factories, city smog, wrong climate and poachers. this way animals would be away from human abuse but we could go and see the animals.
Forth the cost, most zoos are always needing more money for more artificial rocks, plants, water holes, shelters etc. This way habitats would already include NATURAL rocks, plants, water holes, and animals could sleep were they want. Which would mean zoos wouldn't need as much money so people wouldn't have to pay as much to go and see the animals.
Fifth most animals live in groups of their own kind like lions ,orangutans, elephants,buffalo etc.
In zoos animals are put in cages with only one of them in there causing the animal to feel home sick lonely feverish and disrespected.
Would you like to be in a tiny cage with know where to go but the feeding room?
This is why I highly disagree with the zoos now-a-days.