Layman, but: there are perfectly deterministic interpretations. The "default" view (Copenhagen) has randomness, because it's trying to recover a classical measu

Layman, but: there are perfectly deterministic interpretations. The "default" view (Copenhagen) has randomness, because it's trying to recover a classical measurement, but there's views that discard that entirely, such as many-worlds, which is completely deterministic, including measurement, at the expense of discarding any notion of definiteness. Ie. in MW you can't say that "outcome X happened, and outcome Y did not", only "we the observer have become entangled with outcome X." This does difficult things to probability, though there's approaches to recover a notion of likelihood even in this model, such as the decision theoretic approach https://en.wikipedia.org/wiki/Many-worlds_interpretation#Decision_theory https://en.wikipedia.org/wiki/Many-worlds_interpretation#Dec... where they :layman handwave: show that the Born probabilities are the only consistent assignment that exists at all, or something. I also vaguely remember reading an approach that showed that looking back at the ultimate history of the universe, all but a vanishing fraction of branches had experienced histories consistent with the Born rule, but I don't have a link or name for that. Anyways, in a MW universe there's no probability, because every outcome occurs, but there's still "indexical uncertainty", which is to say you don't necessarily know which branch of the universe you are presently inhabiting. Addendum: All (surviving) QM interpretations are empirically equivalent, anyways, so this is purely a philosophical question.