Firstly, humanity has tentative grasps as to why the universe exists and came in being, and further, just because we haven’t reached the level of science to explain it, doesn’t mean the explanation is “god”.
Ancient peoples also didn’t know what lightning was or how it worked, so they chalked it up to gods. Where they right? No, that’s silly now as we can perfectly describe the chemistry, physics, and environmental sciences behind lightning, and even create our own.