Lack of immigration? Where did you get that from? Iceland had quite a high rate of immigration. In Sweden, 30% are either foreign born or have foreign born parents, with the largest immigrant group being from Asia.
https://www.pewresearch.org/short-reads/2023/01/13/monthly-e...
Nearly the entirely population of Iceland came to the US in a single month. The scale of immigration here is very hard to compare with anything the EU sees.
17k people migrated to Iceland last year, or about 4.3% of the total population.
The United States 200k is about 0.06% of the population.
Have you been to Iceland? There's loads of non-Icelandic people living there. About 16.3% of the entire country's population[1], and in some areas it's close to 30%.[2]
The highest number of immigrants in the US are in CA, where it's ~23%,[3], and the country average is about 14%.[4] Although this number is no doubt higher in some cities like SF and LA. But as a country, Iceland has roughly the same or more immigrants than the US.
[1]: https://icelandmonitor.mbl.is/news/politics_and_society/2022...
[2]: https://icelandmonitor.mbl.is/news/news/2021/10/20/immigrant...
[3]: https://www.ppic.org/publication/immigrants-in-california/
[4]: https://www.pewresearch.org/hispanic/2020/08/20/facts-on-u-s...
It's not. Lots of European countries have comparable or greater immigration rates than the US. And the EU as a whole is soaking up a huge number of Ukrainian refugees.