Customer service chatbots have been a thing for years. With LLMs I expect them to become both much better and much more widespread. This question isn't about that. This question is about whether the same thing will happen with phone lines, i.e. audio input and output. I assume the technical issues are much harder but I don't really know. 

This market resolves YES if, in my opinion, AI phone lines are widespread and normal by the start of 2029. I'll consider the international context, but I'm based in the UK - maybe that will affect my judgement a bit. They don't need to be being used by a majority of companies, but it needs to be more than a handful of experimental examples. I'm hoping it will be obvious one way or another. If it's not, I may resolve PROB based on how confident I am that AI phone lines are normal. 

I will consider arguments and evidence presented in the comments but at the end of the day I'll use my judgement. I will not bet in this market. 