Treating the universe as deterministic is an artifact of how laws have been written down since Newton, not a fact about the world.

Physics hardly even acknowledges that the universe is random at its base. We like to think we live in a deterministic universe and everything’s deterministic. But I think that’s probably an artifact of the way that we’ve written down laws of physics since Newton invented modern physics and his conception of motion and gravity, which he formulated laws that had initial conditions and fixed dynamical laws.