Physics (modern physics) does seem to say we live in a deterministic universe due to physical laws. However, that doesn't mean we live in a fully predictable universe per chaos theory.
It also doesn't mean we DON'T live in a fully predictable universe. It only means we don't have sufficient knowledge and processing power to determine chaotic predictability with perfect accuracy. For this reason, whether we live in a deterministic universe under the illusion of free will or we truly have free will is indistinguishable to us - at least for now.