Conversely, when you already collaborate with people in Dropbox, mainly via files, having real time co-editable docs under same folder with same sharing was nice, esp. for people who never remember where they put stuff :-)

Integration was not perfect, but it does create a json .paper file containing a url. But at least it makes you aware the doc exists every time you look at the folder.

Alas, with Paper desktop & mobile apps being deprecated, that's increasingly useless :-( Will the main app at least take over the ability to [double-]click these .paper docs to open them in a browser?