Animals are constantly put in to situations that arr forceful and horrifying to the animals. And they are forced to perform out of fear if they don't obey the "trainers". All of the animals that are in the circus cannot be released back into the wild because of the traumatic experiences they have had.
Animals are dangerous and so its makes it more exciting. The best time i ever saw was a tiger trying to take on his trainer who stayed cool and whipped the animal into submission. The crowd loved it. I think animals are used for all sorts of stuff so why not circuses?
India thinks extremely highly of elephants, so yes, it makes sense that they would not be supporters of them being used as entertainers. Outside of India, the sentiment towards the animal isn't the same. There are certainly animal cruelty discussions worth having, but this isn't really one of them in my opinion. We don't need to do it because India does it.
While a lot of circuses may mistreat animals and have a not so great reputation I don't think that means that all circuses have that same issue. If a circus is responsible enough I don't think that a ban would really be necessary. It really may depend on the specific circus to see if it works or not.