Me right now, so a human that's able to help with pretty much any query. I can understand how having to use a chat widget with someone unhelpful replying would be a bad experience though e.g. a sales person when you had a support request, or a bot that can't help with your support request.

Most chat widgets are set up to forward chat messages via email if there's nobody around and both sides can jump back on the chat widget later if they're both available at the same time which is still an improvement over just email in my opinion.