I think part of it is cultural. The majority of Americans speak English as a primary language, and there's only one set of federal laws. That makes it easier to

I think part of it is cultural. The majority of Americans speak English as a primary language, and there's only one set of federal laws. That makes it easier to grow your userbase.The EU has a large number of residents, but also has 24 official languages, and the member countries have much more distinct cultures. Localization can be a huge problem for startups there. The potential for growth and access to investment capital means tech companies can and do pay engineers very well. Of course there is China, but China also has a lot of unicorns, and it looks like Chinese developers get paid a lot of money compared to the average income.