Both questions could fill many books. But having grown up in Canada and having visited Europe, they both seem to have a fundamental disinterest in technology and futuristic-ness, and curiosity in and ambitions about it (relative to the US). There are still techies and nerds, but they are fewer and further between, and more consumerist and casual about it. From personal experience, in the 90's and 2000's, far fewer businesses were interested in websites or using the Internet for commerce, and were slow to adopt it. In Canada, broadband and cellular access lagged far behind the US, and continues to be sub-par and overpriced to this day.

If you did happen to end up with computer-related skills or education, not only was the pay vastly higher in the US, that's where the culture was a lot more enthusiastic about technology (hence why most of the world's major tech companies were founded there). And if your interest in tech extended beyond making money, you probably felt like you would meet more like-minded people in the US.