At least phone trees are deterministic and there's still (usually) an option to get to a person for matters that aren't covered by the multiple choice options. Talking to AI is a much worse experience and the hope of the industry is that there won't need to be a human as a fallback anymore because (they believe) the AI is intelligent enough to handle anything.
I'm surprised to find so many people who consider human-based customer support a good experience. I wasted an hour on the phone last month with a series of polite support agents who I'm sure were wonderful people in their personal lives. They kept saying they'd like to try one more thing, making me wait 5 minutes (just short enough that I can't get anything done in the interim!), and then asking for one more pointless permutation of the workflow that did not work because their website was not showing me a button the support scripts said should be there. Talking to an LLM would have let me realize a lot faster that we weren't getting anywhere.