On the contrary, humans would try to eat animals if they were immortal in order to become immortal themselves.
What if Japan hadn't become an isolationist country?
Almost the whole population would leave for a dimension to escape their troubles here. And who wouldn't want to go to an alternate dimension?
What if our lives we are living at this second was just a dream we haven't woken up from, and we are actually living completely different lives on the other side?