Calling something "lefty pseudo-science" isn't an argument - they use logical reasoning and support it with empirical data. For sure, developing countries productivity growth is much higher. But globalisation should bring increasing productivity - more options for trade. Not sure about financialisation although I'd lean towards agreeing with you. This guy puts the technology point quite well - https://www.amazon.co.uk/Summary-Rise-Fall-American-Growth/dp/1683780485/ref=sr_1_1?s=books&ie=UTF8&qid=1515180995&sr=1-1&keywords=rise+and+fall+of+american+growth

But intuitively, early twentieth century had incredible changes compare the 21st century invention of a smartphone with the invention of phones and telecommunication. Before the phone, people lived in a world confined to their village or town.News spread very slowly. A smartphone is an improvement over a phone, but it's not a completely different uphaul of society (obviously quite hard to define what an "uphaul of society" is though!).