Right I see, could be useful if you're constantly switching between conversations on multiple platforms I guess. Which come to think of it I am. I only have the Instagram app because typing goes nuts when I try to message on their web interface.
Way back when I was running Ubuntu (like over a decade ago) there were a chat application that would combine Facebook chat, MSN (lol) and a bunch of others and it was very handy to have it right there on the desktop.