rather than an object that we know has no causal effects beyond it's physical properties

They didn't know. They saw the sun helped plants grow and gave warmth so they assumed it was some higher power watching over them.

As opposed to theistic religions who looked at the world around them, assumed that it was far too complicated to exist without a creator for no other reason than "it just seems right", and then promptly used their "loving creators" to justify all sorts of horrific atrocities and wage war and genocide

and before you start, no. Religions like Christianity are responsible for far more death and destruction than natives ever were