As this video reveals, it is (for some reason) fun for a group of people to believe in an imaginary being:
And when the imaginary beings are removed, it is, for many, less fun. To the point of being boring and empty. Why this is so is unclear.
This is exactly what happens with “God”. An imaginary being is created. He is talked about, credited for many things happening in our world, consulted for wisdom, used as an authority to justify different actions, etc. Everyone knows he is imaginary, but they keep him around because it is more fun that way.