It's a power law. The middle class also grew, less substantially. 86% of the world's population are wealthy enough to afford to own a smart phone. To me, that's pretty amazing.
I think that it is fair to attribute some of the ubiquity of smart phones to capitalism. However, I think that technological development is also a big factor. Even the least capitalistic/industrialized parts of the world are dramatically more technologically advanced than they where 100 years ago.
I think the point is that capitalism drives that technological innovation.
No, you see, only the bad parts of our current society are attributable to capitalism. /s
That's what I was trying to get at. It would be unfair to not give capitalism any of the credit for the advances that we have made (after all, people certainly blame it when things have stagnated), but it's probably also not fair to give it all of the credit. There were technological advances long before capitalism and many (most?) basic research takes place outside of capitalism in academia.
But there's a pretty long way to go from basic research to usable technology for regular people. Of course advancement would happen without capitalism, but would it happen at a similar pace? Society socialism didn't seem to be able to keep up (eg computers).
The Nordic countries do a lot of research & product development and they are social democracies which is a moderate form of socialism.