As far as I understand it (and I admit my understanding has limits), an atheistic worldview is an entirely physical/material worldview. In this worldview, everything behaves in a deterministic way. Every effect has a cause. Even chaos theory recognises determinism, just that due to the limits of human observation the approximate present does not determine the approximate future.
Let’s just imagine, for a minute, that the human powers of measurement and observation approached perfection. Or if not human, then something somewhere had that ability. And all physical mechanisms were perfectly understood. Then the future state of everything could be perfectly predicted, including your and my choices, assuming that consciousness was a part of the material universe and conformed to physical laws.
Therefore in a materialist (atheist) worldview, everything is known or determined (even if humans do not yet have insight into the future). There is no freedom. No choice. Just the illusion of it. It is in this (atheist) worldview that I have to conclude that my choices are pointless, that there is no free will, and that everything that was going to happen is already determined. The script is already written.
Yet we experience what we believe is freedom of choice, free will. As I have written previously, that freedom is awesome! Atheism cannot adequately account for it. Perhaps we need to reconsider theism, even though, I agree, accounting for a future-knowing God and free will also presents challenges to our human powers of reason.
Perhaps the new atheists of our day do not yet understand the problems created by choosing not to believe in God.