[jandrewrogers]

London is definitely better than the continent for startups, and you can reasonably build a successful startup there (I have). However, in my experience any of the major US tech hubs still have significant competitive advantages versus London for starting a company.

The business and culture of tech startups is just a really mature and highly developed industry in the US. It started in Silicon Valley but these days it is spread across several cities, and there is more domain specialization by city including Silicon Valley.