You might be thinking that the goal of an FAQ chatbot is to answer the user’s question. That is partly true.
But the main goal of designing a bot is to be able to first understand what question the user asked so you can perform a suitable action.
Suppose you are building your own version of Google Home.
Using ChatGPT to figure out what the user said is only partially helpful, because you need to know the specific task the user wants to do (e.g. turn on the light) and then actually perform an action based on the user’s intent (for example actually turn on the light).
ChatGPT does not provide a way to get this information. All chatbot frameworks, including Dialogflow CX, provide a set of API methods to get this information.