isn’t what is considered improper conduct in a marriage (that gives beis din the right to force him to provide a get) itself defined in halacha?
Not really. “Improper conduct in a marriage” is defined by the society that they are in (for example, as we have discussed, a man in Iran can probably ask to have a burka worn, since that is “Minhag HaMakom”).
For example, the Gemaros in Kesubas that discuss “Hichnis Arba Shefachos” is not dealing with the age of automation.