The complexity of complexity is indeed beyond our thinking for its complexity. We don't know for a fact that everything was made originally from hydrogen and/or helium. That is theory or assumption.
We don't know the complexity of the forces that combine simple things into complex things. The simple conversion of hydrogen into helium (fusion) is something that, in the past, we needed the complexity of an atomic explosion to accomplish. When we do it these days, in the laboratory, in extremely tiny operations, we need a whole lot of complex equipment to do it.
We have no factual evidence of simple to complex conversion without something more complex causing it to happen.
Oooooooooooook...
Well if you go this way we can't discuss anymore ^^
Of course it's a theory, but it's a very solid one. It explains everything we know. It might not be true, in fact the whole science we know is probably wrong, but it explains everything we observe CURRENTLY.
You're actually denying the assumption that Helium and Hydrogene are fusing together in the stars. But spectroscopy allow use to know in a very precise way stars composition. And this theory may be just an assumption, but it explains EXTREMELY WELL the composition of the universe as we observe it. It explains it so well that it is now a worldwide consensus.
I have neither the time nor the energy right now to look deeper in the article you provide about another theory than fusion. You may be right. As I said, we'll probably prove that what we know is wrong in a few decades, that's the main purpose of physic sciences: to be demonstrated wrong and then go further. Maybe your theory explains better the lithium mystery I don't know.
But the theory I'm providing is without any doubt the actual consensus at the moment. So it is a proof in my point of view.
If you need another example of simple things creating something complex then just think about life and evolution: we come from monkeys (not exactly I know but you know what I mean xD), so the complex comes from the simple. Same for most chemical reaction involving fusion, or complex formation.
I know that it is difficult to discuss. And it is difficult to know for fact with our limited abilities.
The point I am trying to make is that complexity does not come about from something simple without a lot of even more complex forces directing it to happen this way. We have no evidence of this anywhere. The best we have are theories or guesses.
The thing that we see all around us when looking for what makes complexity is, greater complexity makes complexity. Since the complexity of human intelligence, awareness, and identity are readily seen all over the place, throughout the whole world, Whatever caused this complexity to happen must have been way more complex in all these areas. The "Whatever" matches the definitions of "God" in our encyclopedias and dictionaries.