Who the hell still uses Dropbox when there are superior offerings like Google Photos/Drive. In fact even OneDrive is better from a reliability and cost viewpoint.
I agree Google has screwed up the choice of communication offerings. But from a use case point, one can very well argue why need one for messaging and one for talking (iMessage and Facetime). Instead WhatsApp does everything in one - dead simple. (In fact, Skype did this too but they never properly capitalized).