I sincerely believe a cat or a dog is far healthier than an LLM for handling social isolation. No, cats can't talk. But they have needs and desires and real emotions. A friendship with an intelligent, social animal is a real relationship with gives-and-takes, ups and downs.
But an LLM only ever wants to do what you want to do. It always wants to talk about what you want to talk about. Unlike a dog, an LLM will never selfishly ask you to play a ball game you personally find boring, and unlike an LLM you will be happy to experience a bit of tedium if it means your friend is having fun. And of course humanity has yet to build an AI as intelligent as a cat: you will be surprised at the number of modern human things they can "1-shot", and permanently unconvinced of any pseudoscience around "evolutionary training data" analogies between biological brains and ANNs.
A friendship with an LLM seems like the social equivalent of a narcotic. I cannot imagine it is healthy for your