A few of the chatbots I worked on, back when I did that, were actually good. Those companies had actually looked at their support traffic and figured out that like 95% of it was people asking the same 20 or so questions that had specific answers. Or at least that you could get to a specific answer with 1-2 followup questions. Like, a huge number of people just want to know how to pay their bill, and the answer is "go to this webpage or call this number".

It's kind of a waste of human time and effort to have a human answering all those questions, so the chatbot dealt with those (and tbh it was 50-50 whether those people even knew they were talking to a robot) and the actual hard shit got a warm transfer to a human agent who got the chat transcript.

Honestly the companies it worked best for, either their online documentation was a total shitshow so the chatbot was your best hope of actually finding anything, or a huge proportion of their customer base were total luddites who just didn't want to use a website and wanted to talk to someone. (We had to make our chatbots support Internet Explorer 11. In 2021. Because for some of our clients IE11 was like 30% of their traffic. I don't even fucking know.)