The jews prove

That's the worst, most atypical metric to use of human behavior. Immigrants do adapt, but only up to a point and that point is entirely dependent on how similar their cultures were to start with. Drop a Englishman in France and he'll be a fish out of water for a while, but adopt local conventions. He'll never be French but will try not to be disruptive and won't try to turn France into England. Because even though they're different cultures, they have similar values.

If you have a group with the core values of taking everything you can and every one else being their slaves, of course even slight assimilation is impossible

The jews prove

That's the worst, most atypical metric to use of human behavior. Immigrants do adapt, but only up to a point and that point is entirely dependent on how similar their cultures were to start with. Drop a Englishman in France and he'll be a fish out of water for a while, but adopt local conventions. He'll never be French but will try not to be disruptive and won't try to turn France into England. Because even though they're different cultures, they've have similar values.

If you have a group with the core values of taking everything you can and every one else being their slaves, of course even slight assimilation is impossible