Commentary On New Year’s Eve of 2019, revelers gathered around the globe to ring in a new decade. Many jubilantly attended “Roaring Twenties” parties, adorned in elegant evening wear, cloche and Panama hats, and knickerbockers, harkening back to an exciting, culturally vibrant era of economic prosperity. But whatever veiled hopes partygoers had for a booming future soon met jarring realities: a once-in-a-century pandemic, global lockdowns, an economic recession, and widespread civil unrest stemming from an incident of police brutality. The Roaring 2020s were not to be, it seemed. Take heart: Mark P. Mills, a physicist, senior fellow at the Manhattan Institute, faculty fellow at Northwestern University, and a partner in Montrose Lane, an energy-tech venture fund, is out to rekindle our collectively dashed hopes. In his new book, “The Cloud Revolution: How the Convergence of New Technologies Will Unleash the Next Economic Boom and a Roaring 2020s,” Mills convincingly argues with verve, …