I feel like this is not new, isn't this exactly what cursor allows you to do? Isn't this just called the orchestration pattern or something? Is it just the UX that you are focusing on here?

Lots of little tools run multiple agents. None of them are really good though. Android Studio. for instance, does it by opening new tabs for each agent. But again, it's not really that great of a UX. Most of the time I revert back to just one or two agents at a time.