The words ethnicity and race/racism are just words meant to separate is all. We are all one human race So guys, think about this here.
Old, young, and age. Those are words that separate us as well. We are not all the same age. No one here is using the word ethncity in the way you posted. They are all proud of their background and countries.
Hmmm... If you think about demographic that is measured it is meant to separate. Age is understandable. They've lived on Earth longer and they've experienced more. No matter how old, senile or wrong they may be.