My wife and I own a restaurant. It's a tough business.
I feel like there must be more interest among native-born Americans in foreign food these days, based on the fact there's 3 Uzbek restaurants within a couple of neighboring cities (which are maybe 200k people total). There's apparently only ~2000 Uzbek-Americans in all of northern IL! And mostly concentrated over an hour's drive away from where these restaurants are.
That said, my wife and I were very interested to try the Tashkent bread. I think this article calls it out - it's better very fresh. It was really good, but not as amazing as we expected (maybe lunch is the time to dine at the Uzbek place closest to us).
I still find it amazing that even (probably) family-run restaurants for such a niche cuisine can make a go of it. I take it as a good sign about American dining preferences.
Much of the Uzbek and Central Asian community is largely located in the Bay, NYC, and DMV. There are around 3 Uzbek restaurants in SF alone.
I guess if you're a migrant, an ethnic restaurant (is that term politically correct?) is one of the most obvious businesses you can start.
The Thai government used to sponsor (not sure if they still do) Thai diaspora who want to open a restaurant in a foreign country, it was their way to market the country and attract tourists.