What seems most bothersome to me (if at all), is lack of a choice to choose no god from the present lineup. At least that one other possible choice.
However in being able to make that choice is not a declaration of Atheism since that of itself is a belief system.
There must be a history somewhere in time before memory, where gods didn’t exist in some ancient cultures.
You’d probably have to get into a whole philosophical discussion about what constitutes consciousness (of self). Then you can discuss whether a culture without sufficiently advanced language to transmit their ideas could qualify as having gods or a religion - and it only gets murkier from there.
Probably worship in some form existed prior to ‘modern man’ even evolving though. It’s one of the few constants of all ancient cultures (that we know of) to have or have had belief in gods, spirits or what have you.