You're giving "quantum" a lot of categorical definition but "quantum" is just as much a set of tools for modeling intractably probabilistic systems as it is for objectively describing microscopic realms.

And anyhow there's _plenty_ of theoretical justification for modeling things like this with various tools from quantum theory:

https://philpapers.org/rec/BUSQMO-2 https://link.springer.com/book/10.1007/978-3-642-05101-2