As Outrider has said the age of polytheism is largely over Monotheism not so, Hinduism has developed it's own monist monotheism.
No, that's pretty much exactly the opposite of what Outrider said, that's what you tried to argue in response without actually addressing the argument. I pointed out that Christianity is a polytheistic belief system trying to claim monotheism, perhaps as an attempt to distances itself from 'primitive' earlier belief systems. I'm not that familiar with Hinduism, but I'm led to believe that whilst some interpretations see the array of godheads as manifestations of a single divinity that only one school of thought amongst many.
One that is able to cross cultures
But not all cultures. Sometimes it encounters cultures where it just withers - cultures with advanced education and social welfare systems that mean people don't need to try to find a philosophy to help them endure strife they don't really need to.
The abrahamic monotheisms
Islam and Judaeism?
and Buddhism have been able to do this and that is why they are referred to as world religions.
They are described as world religions because they have significant purchase across the world; you might choose to interpret that as something related to monotheism, but then you'd have to explain why Paganism and Christianity are also world religions.
Christianity has been going for 2000 years and has survived where geopolitical and geoscivilisations have failed and has even survived the upheaval.
So has Shinto, and other Animistic belief systems, to one extent or another. So has Judaeism. Christianity isn't special in that regard.
Cosmology and science starts with religion and proceeds with the idea that laws govern a reasonable cosmos.
Neither Cosmology nor science more broadly 'starts' with religion; they start with questions that religion hasn't been able to satisfactorily answer, and then go on to demonstrate why many of the questions religion thought it had satisfactorily answered it had actually got wrong. Religion - Christianity, at least, and many of the others - does not proceed with the idea that laws govern a reasonable cosmos, it starts with the idea that god is the magic that can overwrite the reasonable laws to perform 'miracles'.
O.