Why do you want people with foreign backgrounds to “assimilate”? If you were to move to France, are you going to abandon your own language, culture, and play-pretend to be a Frenchman?
If you live somewhere long enough, know the country, work and handle daily life without issues, have social connections with other people in this society, understand at least some language - in my opinion you are as integrated in that country as needed.
If you live somewhere long enough, know the country, work and handle daily life without issues, have social connections with other people in this society, understand at least some language - in my opinion you are as integrated in that country as needed.