Too many reasons to summarize well. I grew up in secular Canada and studied philosophy, so I wasn't indoctrinated into a religion as a child, although I went to Hebrew school and celebrated the Jewish high holidays. The more educated a person is, and the more technologically developed and secular the person's society, the more likely he or she will be skeptical of religions.

I've laid out my criticisms of theism and my reasons for atheism and for philosophical naturalism in many articles:

https://benjamincain8.medium.com/list/gods-funeral-3c9e5930a167

https://benjamincain8.medium.com/list/the-absurdity-of-god-397360389565

https://benjamincain8.medium.com/list/christianity-and-islam-dad5c0d7814b

https://medium.com/@benjamincain8/list/eastern-religions-and-mysticism-8203f5140be7

https://benjamincain8.medium.com/list/the-absurdity-of-godlessness-56cbecdc01af

https://benjamincain8.medium.com/list/secrets-of-philosophy-ea523782c3e1