What about the historical fact of polytheism with regard to gods?

There's Shinto/animism, where just about everything is a god/spirit.
There's the Greek pantheon of elitist soap opera fickle pricks, playing chess with mortals, susceptible to bribes.
There's the Egyptian animal headed figures of the immortal other world (a bit alien/weird from my point of view).

You could just as well ascribe kingship/sovereign to a God who is the arbiter of law/morality/truth/duty/value/identity.

Maybe loosely the family stands in relation to the patriarch as the village stands in relation to the king/leader.

God is probably a strong model/reflection for the head of the household in a Christian context. The figure informs and is informed by the social reality of those who live by it.

Guess Italians traditionally love the Madonna because they prefer mom to dad. Mamma mia (oh mother).
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The fragmentation of old cultures with the turn of the englightenment and technological age, Capitalist commodification, alienation, atomization, might bear some responsibility for a nostalgia of more simple yesterday, when you could find answers/guidance in God. This surely parallels the individual's crisis of having to go out into a shitty world, after leaving family, and pull on one's bootstraps in the nihilistic rat race. Maybe if we had a God (imaginary parent) we could pray for guidance. But who believes in that anymore?

God and Gods fill such a vast, and largely unexamined, need, that they will never go away. Their services will always be required, by some. — hypericin

New people are born on daily basis, there will always be fresh flesh willing to experience God.
What you or me learned or concluded, ex. such that there is no God or that God is something else or anything that would undermine God does not have any effect on new flesh being born.
There will always be new people.

What about the historical fact of polytheism with regard to gods? — Nils Loc

Historically child rearing was collective in the community. Maybe not for every polytheistic ancient culture, but these were historically nearer to hunter gatherers, from which some residue of religious tradition might remain.

But anyway, I don't want to argue so strongly that this dynamic is solely responsible for theism, in all times and cultures. Just that in western culture that it was a salient, maybe predominant factor, in its origin and/or persistence.

You could just as well ascribe kingship/sovereign to a God who is the arbiter of law/morality/truth/duty/value/identity. — Nils Loc

I think this is also likely true.

The figure informs and is informed by the social reality of those who live by it. — Nils Loc

Agreed.

It sounds like there would be, from your analysis, a large conversion to religion, on the cusp of adulthood. Or a reinvigoration of religious worship at that time. Like a lot of teenagers who don't consider themselves believing Christians and then do. Also, in other religions. Perhaps it would happen earlier, since parents get clearly fallible earlier. Is this the case that people become religious or more religious at those ages?

Don't most religious people in the world stay religious from childhood?