People in the past weren’t us in different clothes and religion was basically fulfilling political and cultural functions as well. Like today was have mass media and entertainment, at one point religion was basically entertainment as well. People loved having some preacher come to town and do his show, it was what people talked about. Now we have TV shows and movies etc, and a lot of our media has shocking moral implications just as we’d judge religion in the past for. Not all that different. That leads in to civil/civic religion which is practiced by many today and provides a framework for things like a national identity. When you stand for an anthem you’re performing a civil religious ritual, visiting historical/cultural sites is a sort of pilgrimage.

The form that religion evolved through in history was also defined by the conditions of the society and a lot of times compromises with neighboring powers. Viewing religion as a dumb thing for stupid people is intuitively tempting, but it’s ahistorical in that it says more about our views today (including religous/civil religious views) than it does about what people were like in the past.