https://www.wired.com/insights/2012/05/social-mobile-cloud/
Some people rolled their eyes, maybe including myself at time. (I was never dismissive publicly, but probably didn't pay as much attention as I could have). I would have to say that the buzzword turned out to be pretty accurate: those 3 things largely defined the last decade in terms of software technology, as I see it.
Especially for young people -- there is no world where they don't use some form of social media on their phones (including ones that didn't exist in 2012).
They use cloud applications rather than desktop ones -- that's the "default". Businesses also use cloud infrastructure -- that's the "default".
Lots of money was made in these 3 areas.