Latin for ‘similar’ is similis.
Latin for ‘different’ is alium.
Britain was a nation of similigration or simmigration. New peoples arrived but they were of same race. They were all white Europeans. As such, they could easily blend into the native Britons and become part of Britannia.
What is happening now is aliumigration, and these new non-white immigrants stand apart from the natives. They don’t blend with the natives and become 'invisible'. They stick out visibly and obviously, and they themselves are all-too-aware of the difference between themselves and native Britons.
And in cases where whites and non-whites interbreed, the offsprings stand apart from whites and non-whites.
Who/whom matters in immigration. Similigration blends with the native population. Aliumigration contends with the native population.
Jews arriving in Israel is Simmigration. It boosts Jewish numbers and power.
But if Israel were to allow massive arrivals of Arab Muslims, it would be Aliumigration, and newcomers will weaken and undermine Jewish demographics and power eventually.