Imagine a world without organised religion, where it doesn’t affect people’s lives, but atheism still exists. What purpose would atheism fill in this scenario?
Why must it?
Also, why do you think atheism is an entire atheist’s identity and not just a small part of it? I’m an atheist. I’m also a Trekkie. I’d say Star Trek is a much bigger part of my life than atheism.
Also a much better source of morals (if you don’t think they are innate).