Why you don't see these things is because God didn't provide an encyclopedia about the universe rather a holy book from the context of the last prophet (pbuh) and previous holy books were sent in the context of certain other prophets.
You asked my opinion. That was it. I would expect a God giving HUMANITY a "Final Revelation" to include ALL of humanity - not just copies of the myths from the people in the area, namely Christians. Chinese, Japanese, Hindu, Aboriginal, Native Americans, Aztec, Mayas, many many MANY different people inhabit Earth.
But, that's neither here not there, I don't think Gods exist so there's no rational for what they'd want to do. In essence, when your talking about Gods, you can just say they did it like this because *make up some bullshit*.
If we did pretend there is a God(s) [or Goddesses(s)] there's absolutely no reason to base a Religion around
Angelic Revelation. There's nothing IN the Qur'an morally that isn't
also found in a Philosophy such as
Buddhism or in Religions where Angelic Revelation doesn't even exist - such as
Shintoism or Native American Faiths. That also includes more modern religions dealing with moral imperatives of the day - such as The Bahai Faith.
-- If the goal is to get people to act morally, you don't need religion at all. This can and is taught in cultures all over the planet, from monotheistic to polytheistic to atheistic to non-theistic. So, THAT obviously isn't the "goal".
-- If the goal is to get people to venerate a God, you don't need religion either because you don't need free-will. Just make little robots to sing your praise. Why waste the time growing one up and brainwashing it to praise you (even making the person fear eternal damnation). So, THAT obviously isn't the "goal".
The goal is what it's always been. People controlling other People. Now, from this frame of reference reference, Gods, Last Prophets and Final Revelation all make good sense. People have been doing that game since the time of the Pharaohs... and before.