Yes, atheism is not a belief, it’s a realisation. One day you realise that you don’t believe, that you are simply not convinced. You don’t decide to be an atheist, you don’t belief in atheism, you simply can’t make yourself belief something that you are not convinced of. It’s not in your control, you haven’t been provided with sufficient (or any) evidence and realise that the label of atheist accurately describes your state of mind.
The difference is that realising you lack belief because of absence of evidence is the product of sound reasoning.
Realising that you do believe in something because of an absence of evidence is not.
Oh, you mean like how I don’t believe in an objective reality beyond my senses because of absence of evidence. And how believing in reality because you don’t personally agree with the evidence against it is unsound.