The piece is not about economies, it's about tech dominance. I agree that he market cap of various companies and the actual earnings they produce are quite diff

The piece is not about economies, it's about tech dominance. I agree that he market cap of various companies and the actual earnings they produce are quite different and highly variable. And it's really about productivity of making money, not the useful activity that money would be made from. But market cap does correlate with concentration of revenue. Some of those companies generate fantastic amounts of profit, and their tech is more widely used than the tech of others. If you don't search with Google or Bing, you might use DuckDuckGo. Any other choices worth mentioning? Computers and their cell-phone forms are an essential infrastructure now. Apple or Microsoft software is essential for people computers, Apple or Google software for phones. And so on. Yes the cash advantages can yield other business advantages like monopolization, and vice versa. Yet all enabled by geographical quirk. He's not exploring in detail the long tail of related high tech. Remove the dominance of "productivity", the dominance of the tech remains.