They don’t co mingle though. They segregate themselves into “Mexican neighborhoods”, “Indian neighborhoods”, etc. They marry and socialize amongst themselves.
Sizeable chunks of some immigrant populations simply won't melt, which IMO is fine in a place like Canada or the US. They'll still work with everyone else, and I feel like profession and class are both way bigger dividers than ethnicity anyway. A white SWE probably knows more Indian SWEs than white janitors.
Speaking a different language at home is a really good thing. Kids are going to pick up English through immersion anyway, so they're going to turn out bi/multilingual. That's great.