Comment by corimaith

To add on this, ethnic heterogeneity (and ethnic enclaves) is one of the shallowest forms of diversity. If you examine the diversity regarding district characteristics and architecture, shopping options, subcultures, etc, many homogenous cities like Tokyo or Hong Kong are far greater and accommodating than London in diversity.

And I would say that one reason for that is the elements I mention is something an individual can take seriously and integrate into their own world, while enclaves stay perpetually from the vantage of exoticism rather than integration.