Why does it not matter that in all of the known world the revelation received by Moses for management of interactions between people — the last six of the ten commandments — has not been surpassed over the course of more than four thousand years? All of modern civil society functions on basis of those six commandments. If the revelation received has practical value, it is not mere visions, it is interaction between man and God for benefit of human interactions.
And if Moses came up with the revelation himself why would he give the credit to God and not take the credit himself? He already was leader and was known to be spiritually dangerous — miracles worked through him (this is true for the story whether or not the miracles are real or myth passed on by that generation of Israelites: either way he already was revered by his people). He did not need to ascribe the commandments to God to get the Israelites to buy in.
Whenever God interacted with people in the Bible, there was purpose to the interaction. The main problem with most atheists who criticize religious writings is they do not seek to understand before they form opinions.
I see you are choosing to think things through — that is the path to self enlightenment — a path I believe Jesus delights in.