Even colors depend on cultures heavily. The ancient greek are believed not to have seperated between yellow and green, other cultures similar.

Internationalization is a lot harder than it seems to most people. And then there’s also accessibility.

Even with traditional UIs where everything is hand made it’s already an extremely huge task, but a conversational UI is far more personal.

It has to deal with things like how much privacy or directness is expected in cultures, with taboos, it has to have a full perceptional model of the person who will hear it to be able to properly handle all this.