We consider ourselves as the apex of development in the world. We are genetically programmed to seek security and certainty in a random world. We create a god to provide that for us and if we are the apex god must be just like us but better and more powerful.

Great question! I think since many (Greeks and Norse in particular) are mapping archetypal elements of the human psyche, human shape is entirely appropriate and expected.

For other mythologies, perhaps it is simply that human consciousness is the highest, most articulate form of consciousness we encounter. It makes a kind of sense that this would extend to the heavenly realms.

It's to do with the 2 hemispheres of the brain, our ego tends to operate in the left hemisphere which is limited in World view, and only 2% connection to the right hemisphere where the real intelligence lies, left knows there is a greater intelligence but is reluctant to give right the compliment, left makes a fantasy "other"
If you want an in depth answer read
Master and emissary by Iain McGilchrist

That’s easy. It’s because all gods are man-made.