I think atheists will argue that G-d is a construct of religion. And you have the starting point all wrong.
They simply believe in what they can observe, what science can observe.
So to say that it's just as likely one way or the other is simply false. Because one is that we are going to make up an answer the other is we don't know yet, but that doesn't mean we will make up an answer and call it G-d.
Iirc Richard Dawkins explains their view on this well.
But that's exactly my point. accepting Darwinism as fact (or even as a viable option)
is ascientific.
As I said in my original post
It's one thing to be agnostic, to say that you can't prove it either way. That's at least a fair argument.
Saying there's no way to know is fine. Saying that science supports the notion that there is no G-d is simply not true.
Darwinism has been effectively disproven. (At least to the intellectually honest.) The big bang theory still has some big unanswered questions. It may be the best theory we have right now, but it's not quite the scientific fact it's made out to be.
Believing those things as fact is a religious belief, not a scientific belief.