It’s not an assumption, it’s an observation.
1. Everything complex comes from something less complex.
2. Supernatural has never been observed or detected
Therefore the universe cannot have come from a supernatural intelligent God who thinks and behaves like a human and shows anger, pride, ego and other human emotions. He pays special attention to one species of primates on a piece of rock in an infinitely large universe and punishes them if they do not stroke his ego. It seems more like the imagination of superstitious ancient people rather than reality.
The God argument is an argument from ignorance. Ancient people made up superstitious stories like this like the big turtle under the earth shaking its back when they couldn’t explain natural phenomena such as Earth Quake and where universe comes from.
From our discussion to me it seems like you are not searching for the truth but trying to justify your irrational beliefs, when there is no evidence, you run to philosophy, when that doesn’t work you try to question philosophy, when that doesn’t work you try to question human senses, when that doesn’t work you want to talk about intuition and consciousness. It’s like you are trying to force a rope through a needle.
The reason why your quest For truth is poisoned from the start is because you are starting with a conclusion that God exists and then trying to find ways to prove that conclusion.
Intelligent people on the other hand study the evidence first and then find the conclusion last. Whether or not God exists shouldn’t even be the starting question.