If the live chat service connects me to a human who is able to resolve my query in a timely manner, I'll take that any day.
Phoning a large company can result in waiting in a call queue for a long time. My attention is on the phone call instead of anything else. A live chat window can be relatively ignored and checked once in a while.
Emailing a large company can result in waiting for a reply taking 3-5 business years. Live chat gets me a response relatively quickly.
A live chat service that does not provide an easy means of interacting with a human and which instead easily allows getting stuck in a bot loop is a great example of poor customer service and, for me, a great way of quickly finding out who to not do business with.
That said, a poor live chat service for a business that I absolutely have to contact (most recently when terminating internet service after moving house) is an exercise in frustration and annoyance that is hard to replicate in any other manner.