most atheists will say one of the reasons they don't believe in gods is a lack of convincing evidence.
That's a huge problem for theism.
It goes hand in hand with the problem that those who claim personal experience of deity largely differ according to the norms of their culture, so that contemplative Hindus never encounter Jesus, and contemplative Christians never encounter Ganesha. Even within the culture, they may report simply an emotional state eg ecstasy or awe, or a dislocated point of view (as with out-of-body experiences, which we can reproduce in the lab and have reasonable explanations for.) No data anywhere.
Yet those same atheists may be totally fine turning around and accepting something like material monism, which also lacks convincing evidence (and is honestly worse than many arguments/evidences for theism).
No, there's abundant evidence for materialism. Perhaps the most direct is the manner in which brain function alters when physically altered, eg by trauma, disease, drugs including alcohol and caffeine, starvation, anoxia, stress and environment.
Were the functions of the brain 'not material', then none of that should happen.
And were the functions of the brain 'not material', then why would the body need a brain at all?
Another point is that on our present understanding the Big Bang consisted solely of energy (or mass-energy, if you prefer that term) and nothing else has been shown to have objective existence.
Of course, if you don't have objective existence, you're imaginary (or non-existent, or both).
Or how Theists are expected to argue and defend their position, yet atheists just have to stand there and say "nah, I don't believe you."
More like, simply ,
If that's true, show me.
If you assert something positive as being correct, then you carry the can for showing its correctness. You can't turn that round and require your colloquist to show you're wrong. This is as true about gods as it is about unicorns. The aunicornists are entitled to say,
Show me, just as the nontheists are.
Which said, it's nonetheless not hard for nontheists to make a persuasive argument against theism.
And then, of course, with the exception of this statement, there are no absolute statements. I admit there's an exquisitely tiny possibility that gods exist (magic as distinct from superscience) and that within that tiny realm there's an exquisitely tiny possibility again that one of them resembles the deity of one's particular choice.
Hard data to the contrary could alter that instantly, but there's none.
Perhaps worse is when certain scientific info is rejected despite being well supported, but any science that doesn't hurt atheism is openly accepted. How do you decided what you will accept and what you won't?
That cries out for an example. What has appeared in reputable journals of science this century in favor of theism that the scientific world has then improperly rejected?
My own view is that the idea of a real god, a god with objective existence, is incoherent. That's why there's no description of a real god, such that if we found a candidate, we could determine whether it was a real god or not. (That's not technically atheism, though the result is very much the same.)