> How often do developers want to edit the same file, at the same time, and have those updates occur in real-time?

That's a very specific example of collaboration. Remote work is exploding. What about, say, integrated, collaborative debugging or code review? Integrations with things like Slack?

I do this all the time. I use a tool that has 2 modes: turn-based and multicursor, the turn-based mode is signnificantly more annoying. Most of the time you just use it to highlight but it's also good to be able to help the other person with typos and comments, while they are focusing on the logic.

Do you never pair?