I'm not convinced GUIs can't be built with functional programming techniques. My GUIs (in Android and more recently with React) generally tend to follow a unidi

I'm not convinced GUIs can't be built with functional programming techniques. My GUIs (in Android and more recently with React) generally tend to follow a unidirectional data flow, where the view building is really a dumb passthrough of massaged data that's stored in a local DB (like SQLite). The view state could be represented ENTIRELY by a JSON object, e.g. and since it's all stored locally, it's replayable if something goes wrong.