The report you refer to actually have Berlin, Bangalore, Sao Paulo, London, Amsterdam, and Tel Avia as the fastest growing startup hubs. I am wondering why some of these aren’t mentioned?
Regardless, as someone who used to be in the startup scene in Seattle, I agree that it is great place for startups. Although you’re probably right about top talents being concentrated in tech giants such as Microsoft and Amazon, I’ve seen more people moving from those companies to startups than the other way around. In a way, it’s like they are attracting talents into Seattle for the startups. Just my 2¢.