Just like life in a cellular automata world could figure out the rules behind cell replication and destruction, they could never peer underneath at the mechanism driving it all. For us, is there a level underneath the quantum level? We can speculate (i.e. string and m-theory), but we may never find out because we're made of matter constrained by three spatial dimensions and our sensing equipment is similarly constrained. For an outside entity observing the universe, it may very well be deterministic, and what we see as quantum probabilities and non-determinism are simply limitations in our ability to build better testing equipment, because we can only work with what the universe provides to us (atoms and particles).

Depends on who you ask. In the Everett interpretation, quantum mechanics is deterministic, and uncertainty about quantum mechanical measurements arises from indexical uncertainty (“which observer am I?”) rather than fundamental randomness.

Why can't cellular automata rules contain a quantum_rand()? [1]

Most games and simulations contain RNG's to make things interesting, quantum uncertainty seems to look very similar to my naive self.

1. https://content.wolfram.com/uploads/sites/34/2020/07/random-...