A great part of an IDE worflow is the visual experience. Having some kind of service, while forcing each client application to create their own UIs, kind of beats the purpose.
This is why on UNIX world the developer experience feels half-baked to those of us that could step a bit into the world as imagined by Xerox PARC.
It's a great part of the workflow for you. For me it's constant visual interruption of flow state.
Nothing about having a service prevents offering that visual experience. IntelliJ/Eclipse the IDE can still exist while consuming the same backend that my Emacs consumes. You get your visual experience that helps you achieve flow state. I get my highly configurable/optimized editor that helps me achieve flow state.
I have never, ever found the "visual experience" to be the reason that I enjoy using an IDE. Besides, even if it were, what about that procludes building a nice UI around existing modules?