Robert Sapolsky's new book (2023) argues that there is no free will, that if we knew the state of all neurons with sufficient accuracy then we could predict a person's behavior. My sister thought I'd enjoy the book as a Christmas present.
I'm only a chapter into it, but I already suspect the key word in that first sentence is "if." The brain is such a morass of tangled neurons that it becomes a chaotic system, and the appearance of free will is the result. Determinism is only as good as the understanding of initial conditions.