Actualy, I think it is. You said it yourself: > on desktop I can't paste between Emacs and Confluence because Atlassian went out of their way to break it. Wh

Actualy, I think it is. You said it yourself: > on desktop I can't paste between Emacs and Confluence because Atlassian went out of their way to break it. Which presupposes that by default (i.e without Atlassian's messing things up), it would have worked. On desktop applications, File-level and copy-paste interoperability are there by default. This is the difference: what is the amount of interoperability you get by default, i.e without specific actions from the app developers? The fact that you can break interoperability is irrelevant.