in our daily lives, we find it easy to produce something simple, and we find it harder to produce something complex.
It is probably natural to associate complexity with intention.
Religious people are forever identifying agency and intention in the universe, and concluding that complex things must have been designed is natural for them.
They have no idea about the concept of emergence. We know that complexity can and does arise from simplicity. Evolution is one such example. Evolution explains complexity because it explains it in terms of a few simple rules. God does not explain complexity because God herself is complex. Complexity is the very thing we are trying to explain, and the religious can only 'explain' it by assuming it in the first place. Complexity, therefore complexity.
https://www.youtube.com/watch?v=FdMzngWchDk