There are a number of services that provide speech-to-text services. Being able to hook a voice chat feed into one of them for live transcripting would be pretty game changing for conferences in general.
Side-tangent, but when i saw it introduced in MS Teams (for recorded meetings, there is now a transcript tab that you can watch in real time as the meeting goes; sorta like live captioning written in a format of a legit transcript that you can read later too), it blew my mind with how useful it was. Not that i need it, but it is super helpful to keep track of who said what and when (nice when you accidentally get distracted for 5 seconds and dont want to get halfway lost), and the transcript even assigns names to what was said.