I don't get your point. Yes London was economically powerful long before high-rises went up. In fact, NYC was economically powerful as soon as the Erie Canal was completed. But the fact remains, in order for a major city to maintain its economic competitiveness, especially in the modern era, they must build skyscrapers. London is further proof of an economically powerful city that cannot stay with traditional 20th century low-rises, starting with Canary Wharf in the 1990s and the rest of the CBD in the mid to late 2000s/early 2010s. In fact, until the development of Canary Wharf, London's population, with the exception of the 1950s, fell each decade until 1990s, when Canary Wharf rejuvenated the city as London emerged as a major financial center in the 1980s. If the logic was that London could stay competitive without building skyscrapers, then why didn't it do so? Do you think London could continue to depress commercial and residential prices without going up? Do you think major corporations would prefer to spread their offices over numerous locations, rather than being confined in a smaller, more efficient area?
Face it. You may have been able to use London as an argument a couple of decades ago but your poster boy for a low-rise city is gone. Time has changed and London (for the better) has changed as well.