I listened to the founders explain that the current process of syncing up to review or question code is very multi-step and sort of inefficient almost adversarial at a high level. A slack mention, Github discussion, screen share, etc it all ends up being kind of disorganized and painful versus just being able to edit the document collaboratively and directly, perhaps leaving some metadata tagged at certain locations (e.g, notes from a conversation about the code).

It's not like the editor prevents one from still using slack and other external tools, either. I guess I just see the value in in-editor integration to handle that stuff more smoothly, at least for those using the same editor.. I can see myself really appreciating the feature if there's a part of the codebase that consistently trips people up or is under active discussion.