[Cthulhu_]

I think instead of calling it collaboratively vs 'offline' is to use the terms reactive vs transactional; reactive means every change is instantly visible everywhere (think changing a configuration in MacOS), transactional is that you have to hit a save button (think file editors, Windows configuration).

I do think you have to be fully in on either one or the other. But collaborative tools are more difficult to do as transactional; that works with version control, but then it's up to the user to deal with conflicts. With reactive applications you have to deal with asynchronous whatnots and eventual consistency, although there's plenty of algorithms and technologies out there to handle that.