How can anyone answer this when the answer is suspect to be a projection of the ego? How can assume to know anything we don't know we don't know, anything outside our experiences? Why does God resemble a human? If chickens held awareness instead of humans, wouldn't God be a chicken? If God lacks temporality or with certain aspects of the such nature, or it's the universe that lacks temporality, or if both exist and are eternal, how could one create the other? Wouldn't it seem better to think the two are one and the same? No, God should hold intelligence, and the universe is mindless. But to say "the universe is" is already paradoxical. Being can't be a condition of the universe with the same aspects as my own being, it seems more likely that omni-qualities transcend that which refers to my own existence. And to speak of such a nature may as well be to speak of an integral. Eternal recurrence? Tetravalent graphs?
But to go back to "why". Why does anyone ask why? Is "why" a product of exclusively human thinking? Is thinking in the way that humans think exclusively human? Or is thinking in general equivalent in any state of consciousness? The development of AI might help to prove that. But let's say thinking as a function is objective. It follows that I can talk about "why" with better grounding. So why I ask why may be due to me not knowing things. In fact, I doubt I really know anything the more I take the relativity ride. What condition then separates knowing from unknowing, absolute to relativity? Does this dichotomy break signal my train of thought futile?
Personally I enjoy the depiction of God as Brahman. One can say anything and everything about Brahman, in every possible just way to prove a point. Brahman is, Brahman is not, Brahman is good, Brahman is evil, yadayadayada
https://www.swami-krishnananda.org/song/song_1.html