The New Siri seems to be quite useful, with "personal context" understanding my calendar, messages, mail etc.
ChatGPT 4 voice mode is very impressive, with the conversation getting clarifications and finding exactly the information I want (when it is not hallucinating). ChatGPT-4o will be amazing if it is as good as what we saw from the demo.
It is not for everyone, but I personally use AI chat every day and find it useful.