Polytheistic religions have more room for multiple worldviews than monotheistic religions. Polytheists have internalized the fact that there can be different paths that are right for different people. That’s why you get so much division in monotheistic religions.
In polytheistic religions, you still get infighting, but it isn’t considered virtuous.
Put another way, monotheism is polytheism except with a single title, Lord of the Universe, that all the gods/theologies/denominations have to compete for in order to be legitimate. That competition of different gods/worldviews is the essential innovation that monotheism brings.
That competition, that need to justify one’s beliefs, provides a drive that monotheists have and polytheists lack. And that is why monotheism prevailed in so many areas.
As far as I know the history, the Roman religion was pluralistic in the sense that you could worship whatever gods you wanted, but you also had to pay respects to the Empire's gods. The monotheists refused to do that for the obvious reason, and that was the primary cause of conflict
Early Christians seemed weird to a lot of the people of the Roman Empire. Sort of how Christians now think of gay and trans people. It was deviant and socially upsetting. Modern Christians would probably not get along with early Christians.
In polytheistic religions, you still get infighting, but it isn’t considered virtuous.
Put another way, monotheism is polytheism except with a single title, Lord of the Universe, that all the gods/theologies/denominations have to compete for in order to be legitimate. That competition of different gods/worldviews is the essential innovation that monotheism brings.
That competition, that need to justify one’s beliefs, provides a drive that monotheists have and polytheists lack. And that is why monotheism prevailed in so many areas.