Noah Smith says Excel did more for economic growth than the social internet: "The big boom in GDP from computerization and the internet was earlier, '90s and early 2000s. By the time we got to Jack Dorsey sitting there in a hoodie giving a voice to the voiceless, the big GDP growth from the internet was over." "The smartphone added so much to GDP, but mostly it just replaced television. The social mobile era was an era of technological stagnation in terms of GDP. Tech was no longer adding…