Earlier quoted context omitted.
You omit the masses of working poor immigrants that do a lot of the manual labour North Americans do not want to do -- predominantly in agriculture, construction, small manufacturing, and healthcare. They're the de-facto essential workers. Europe's struggles seem to be caused more by a culture clash. Immigrants will always bring their way of life with them, and group together - it's a constant of human nature, this i…
The idea that immigrants are a good idea because they do labour your existing population won't do is quite socially destructive and the cause of technological stagnation. It separates people into a de facto caste system where unpleasant jobs are also underpaid, prevents automation from becoming cost effective, and can block a country from reaping the benefits of skilled migration.
I'd love to hear some examples where this has caused technological stagnation and blocked skilled migration -- US and Canada provide solid counter-examples to these claims. Both countries take in immigrants at both ends of the economic spectrum, from coveted H1B high-paying tech jobs, to seasonal farm workers who exist in slavery-like circumstances. Both countries show significant, sustained technological innovation.
I agree this is destructive to the social fabric, and it separates us into strata. But I have a hard time believing that immigration is the cause; a simpler explanation would interpret it as one of the symptoms, with the underlying causes being closely related to the relentless transfer of wealth to an ever-shrinking "elite".