My point is that an agnostic atheist does not have any justification to leave the matter there.
Of course they do. I have never been given any reason to take the idea seriously, so I don't. I have to remain intellectually agnostic simply because there are many versions of God that cannot be
proved wrong.
Many people who state they are agnostic atheists act as though they are gnostic atheists IMV. They are practically convinced that there is no God, certainly enough to forgo an adequate intellectual investigation.
There doesn't appear to be anything to investigate. Theists, in my experience, only have blind faith. wishful thinking, and terrible 'arguments'.
Evidence of that is a pretty shallow knowledge of the philosophy behind theism...
Every time any theist has claimed to use philosophy, it turned out to be total bollocks, like the hour of my life I'll never get back listening to Edward Feser.
Regardless, if you have to delve into philosophy to find a reason to believe in a God then said God clearly isn't interested in delivering a message to humanity. It's not impossible that
some sort of God might exist, but one that is at all interested in clearly communicating its existence and message to humans, goes against all the evidence. If it can't be bothered, then why should I?