Reasons against keeping animals in captivity?

Animals haven't been put on this earth just to live, no not even live because living is actually having a life and being happy. what if you were trapped in a cage like all your life like most of those animals are? you wouldn't like that to happen to you, so why do that to another living thing that cant even defend itself, and it has feeling but all it can do is just nothing because most cages dont let animals even move a all.