As someone who is mostly agnostic, those who belive that absence of evidence equals evidence of absence belong in psychotherapy.
This position is a straw man. Atheists generally do not argue that God categorically does not exist. Instead, we usually say that we don’t believe in God because there is insufficient evidence. Much like the proverbial invisible unicorn in your backyard - since there is no evidence that it exists, there is no reason for it to affect how we go about our daily lives.
When it comes to whether you’re agnostic or atheist, I think it helps to answer the following question on a scale of 0 - 10: How confident are you that God exists? If you say around 5, then you’re agnostic. If you say around 1 or 2, then you’re an atheist.