I think of Singapore Airport.
Which - being an airport - is about as transient as you can possibly get.No community, no common culture, no (historical) shared experiences…just a brief fleeting visit in the present moment, on your way to somewhere else.
Which is maybe a reflection of the experience of modern life.
In disagreement with grand OPs daydream of a multicultural future utopia, the multicultural area of the future probably looks a lot more like multicultural areas of the present and recent past, the burbs of Paris burning, genocide in Africa and the middle east, raping and violence by refugees in Europe. The multicultural world of the future will look a lot like Syria, lets say, but angrier more violent and less functional, and it'll be everywhere not just "over there". Except for the rich people in their gated communities profiting off all of it.
There is no one single 'white culture', you need to at the very least specify 'white American culture', or Scottish/Australian/Russian, etc.
But even if we accepted that false generalisation, I'm rather curious as to how you see us fetishising its suicide. Care to elaborate?