US is literally built on immigration!! Millions of Germans, Italians, Japenese, Persians, Chinese, Indians immigrated to the US since the 18th century.
Benjamin Franklin was very worried about German immigrants in the US and he described them as "less intelligent", "aliens" and that they won't assimilate. Fast forward few decades later/centries later, Germans are one of the most successful immigrants group in the US, industrialising the country, creating financial institutions, and becoming military and political leaders, giving US presidents and generals.
Recently, Asian immigrants created Silicon companies. One of them is a trillion dollar company called Nvidia.
France has a huge success story with immigrants as well, the poles (Marie Curie), the Italians, the Portuguese, North Africans, etc.
There are certain issues here and there, especially with unregulated modern mass migration, but in my opinion, that's not a true representation of real immigration that has always happened since the beginning of time.
The fact that Sweden has integration issues with mass migration from war-torn Syria is a special case.