The way you've written your comment implies "high trust societies" and (presumably ethnic) "diversity" are opposites. The terms high- and low- trust society come from Fukuyama, who considered ethnically homogenous countries like Korea low-trust, and ethnically diverse countries like the US and Germany high- trust. Please, go more into what you mean about social trust and how it relates to diversity.

"diversity" is a weasel word (often commits the motte-and-bailey fallacy) because it can easily mean different things at different times, making it prone to use as a political catch-all slogan.

"Diversity is our strength" -- what kind of diversity? Within a company, diversity of purpose is not a strength, because you can't have people working at cross-purposes with one another. It's the same for countries, local communities, and families. "Diversity" can easily be used to describe what ultimately is "division", making it contradict the old saying in the USA "United we stand, divided we fall".

Diversity of strengths/weaknesses, personalities, backgrounds (including ethnic), etc. all do make us stronger provided we maintain and prioritize a practical unity in a shared purpose.