I type as fast as I talk so for majority of my LLM usage I don't need text to speech.
But I love the chatgpt voice interface e.g. on a long drive when I can use it to learn about random stuff (btw, turn advanced voice off for such usage).
Other part though is, hacker news vs regular population, majority of which would much much rather talk and listen than type and read.
I like to talk (stt) but I don't want tts to talk back to me I just want to read the response. voice synthesis is a waste for me personally.