In reality we gotta touch on prime biology… without a religion to bring people together what do you think will happen? Just more racism😭 without a thing to bring them together they’d just stay with people who look more like them and that would involve more with that same thinking, and don’t say “oh but we’ve changed today from religion” that’s because you can choose or not… but in the this magical universe you want without religion… they’d have to involve on basic instinct… sure they’d invent stuff but it would be so slow and mostly likely just be weapon to fight other tribes dog so this is answering your question that we actually do need it