In some sense, randomness is a modelling choice, not a statement about the underlying mechanism.
Eg we wouldn't be able to tell whether stock prices are truly random (according to some distribution), or governed by a cryptographically secure pseudo random number generator.
Another example: quantum mechanics is a fully deterministic theory. It's even linear, so we don't even get deterministic chaos like from Newtonian billiard balls or the Newtonian three body problem.
But some popular interpretations of quantum mechanics like the Copenhagen Interpretation decide that they need to add randomness to make sense of QM's predictions.
In contrast, some other interpretations like Many Worlds leave QM deterministic.
Eg we wouldn't be able to tell whether stock prices are truly random (according to some distribution), or governed by a cryptographically secure pseudo random number generator.
Another example: quantum mechanics is a fully deterministic theory. It's even linear, so we don't even get deterministic chaos like from Newtonian billiard balls or the Newtonian three body problem.
But some popular interpretations of quantum mechanics like the Copenhagen Interpretation decide that they need to add randomness to make sense of QM's predictions.
In contrast, some other interpretations like Many Worlds leave QM deterministic.