Earlier quoted context omitted.
Absolutely absurd. Why is it people feel the need to make out that western cities are somehow magically immune from the exact same detrimental effects that they happily accept about everywhere else? "Enrichment" is a buzzword for the insulated elite happy that they have new things on their lunch menu, somehow ignoring all the negatives that come with it.
I can't help observing that Britain established a global empire (so vast in scope that they could truthfully say the sun never set upon it, until quite recently) and made it clear to the countries they colonized that Britain, and particularly England, was the center of civilization. We're surrounded by the artefacts of this empire, from Imperial measurements in the USA to Greenwich Mean time being the default timezon…
It's simply that the wealthy benifit from increasing labour supply; this is the "enrichment" you get. Not an improvement in culture or conditions, an increase in wealth concentration.
It's entirely reasonable for a citizen in an English speaking nation to complain about other languages becoming common, as it is direct evidence of the migration policy that is doing them harm.