Except... In IDEs you can have code side by side, and then a tool running in a third pane (let's say a debugger, or tests), and you have quick and convenient shortcuts to switch between these panes, and hidden panes, and other windows on desktop.
Phones have none of that. And they really can't really provide them because of limited screen estate and touch being the only way to interact with it.
This mode seems suited for mobile UIs, so that flexibility should get them pretty close to being convergent. There probably still need to be some adjustments to make it really usable on mobile, but a lot of the work has already been done.