But Switzerland emphatically does not have a homogenous population. It has an exceptionally diverse population, linguistically, religiously and culturally. And yet as you say it has an exceptional record when it comes to cohesion and social trust. Living the dream!
I’d point out two things:
1) While Switzerland combines several ethnicities and cultures, the fusion dates back almost a millennium. The Old Swiss Confederacy arose in the 14th century, before Italian, French, and Romansh were even recognized as separate languages.
2) The Swiss federal structure goes to great lengths to give autonomy to the distinct groups.
So it’s not accurate to say that Switzerland is “homogenous” in the same way Denmark is homogenous. But it’s not like Switzerland’s Italian-speaking population grew from nearly 0% to the current 8% over a period of a few decades. There is a common umbrella identity encompassing these groups that dates back a long time.
Can you list the statistics that demonstrate the exceptionally diverse population?
The social cohesion of Switzerland is mainly within the linguistic communities. Many Francophone Swiss hardly speak a word of German (just as their Belgian counterparts don't speak Dutch). And a large proportion of Switzerland's "diverse" immigrants are in fact from just across the country's borders (particularly Germans). "Diversity" is not what explains Switzerland's wealth.