Does this need to be a new product? Yes.
There are no great collaboration tools for developers I've ever seen like this. I'm immediately willing to pay whatever it costs to get this for my team. No more awkward calls trying to communicate complex concepts that don't often have terminology unless you make it up. Quickly highlight and explain a conflict without back and forth or frustration about how and where it fails over 5 minutes, just kindly ask if they wouldn't mind and start editing in the use-case or failure-case to explain the concept instantly.
Have you ever had to grab someone's mouse and keyboard awkwardly to get to the point of a conversation or feature? You never have the need to do that again.
Ever had the displeasure of trying to explain something that couldn't be explained by text / call in person over their shoulder ending up back-seat driving? Never again.