Wouldn’t text to Siri be considered a chatbot? This is the Wikipedia definition of chatbot. I think Siri would apply.
A chatbot (originally chatterbot) is a software application or web interface that is designed to mimic human conversation through text or voice interactions.
Yes, you can chat to it, verbally or with text, but it’s not doing generative output in the same way that ChatGPT is. Siri is deliberately kept out of that danger zone.