You’re both wrong and you’re both right. A religion is just everything people think is important and needs to be believed by everyone. The “one single cause of religion” is that humans pass on knowledge. They teach each other. Obviously, this will result in socially organised systems of belief, AKA religions. And if you’re asking “why is the content of religions incorrect”, it’s because human beings weren’t born with omniscience. Your theories apply to why the content of religions is what it is, but not to why religion itself exists.
You’re both wrong and you’re both right. A religion is just everything people think is important and needs to be believed by everyone. The “one single cause of religion” is that humans pass on knowledge. They teach each other. Obviously, this will result in socially organised systems of belief, AKA religions. And if you’re asking “why is the content of religions incorrect”, it’s because human beings weren’t born with omniscience. Your theories apply to why the content of religions is what it is, but not to why religion itself exists.