They are mostly from one region of India.
And Patel is just a common name, it doesn’t mean you’re in the same tribe. Especially since in the old days tribes were frequently family oriented and religion was a big part of family.
But tribes keep changing. When everyone was immigrating and desperate, they acted as one and helped each other. Now, the successful ones and 2nd generations americans who can stand on their own have become their own tribe. They’re not going to reach out to their 2nd cousins who are poor and don’t know English well.
Now there are new tribes, mostly split along socioeconomic and education lines, regardless of religion.
https://www.nytimes.com/1999/07/04/magazine/a-patel-motel-ca...
As a Canadian who has lived many years in the US, the casual use of racial descriptors still shocks me. I find is very discomforting to be asked my race on forms, to see national news talk about how different ethnic groups feel about this or that.
This year added several options to the race question, including Vietnamese, Indian (East), Guamanian, Samoan, and re-added Aleut.
https://en.m.wikipedia.org/wiki/Race_and_ethnicity_in_the_Un...
On your latter point, absolutely. And the people who make make the biggest effort to categorize people into hyphenated-Americans are the very ones who turn around and accuse people of being some-kinda-phobic or some-sorta-ist if they don't see the world that way.