Agnostic means "its not possible to truly know" that there isn't a god, right?
It seems to me that it is perfectly possible to truly know that, just like a lot of other things I dont believe in that are obviously not real, but I havent got to disprove them myself to know that, or see some scientific proof or watch a TED talk about it to know that.
Like Heaven and Hell or the devil, if you asked "do you believe in the devil?" instead of God, a lot more people would be definitive (I think) - even if you gave them the same agnostic option.
While that might be true (and I think it's very probable), logic would still dictate the agnostic stance on it. As I said, you can't disprove a negative. It's just like with most atheists, internet debates aside, there is very little reason to argue about something nobody has any evidence for.
Like, I actually noticed this with myself, I never talk about this stuff in real life. I am an atheist, most of my friends are atheists, even with friends who believe the topic never comes up. And that's for a topic so ingrained into society that it's almost impossible to get rid off. It's actually so ingrained that this is probably the only topic where people actually have to point out that they are agnostic somethings.
If religion didn't predate science by a few dozen millenia we would not have to have this conversation (over and over and over again). Talking about god or gods would probably be in the same category as talking about unicorns, gnomes, or the flying spaghetti monster. And people wouldn't have to say I'm an agnostic atheist, just an atheist, the rest would be just as implicit as if we were talking about most other nonsense.