I would certainly not say that being an atheist is a more moral position than being religious.
A religious person, OTOH, is very likely to say that being religious is a more moral position than being an atheist.
If an atheist disagrees with that assessment, and explains why their moral system is adequate, the religious person will oft accuse the atheist of trying to be superior.
The fact that we atheists actually think about our morals, rather than simply accept them as given, does, IMHO, make the atheist in a better position to understand and defend their morals.
I still remember a religious debate with Lawrence Krauss where his opponent said that his belief in God was all that was preventing him from being a murderer. That’s not, once again IMHO, a morally superior position.