There might be 5,000 different ethnic groups, but there are only three or four different races: Caucasian, Negroid, Mongoloid and Australoid. Or European, African, Asian and Australian aborigine.
This calling numerous different groups a different race is a lot of PC nonsense many have adopted so they can throw the racism charges around and more groups can claim to be victims of racism.
If they are genetically distinct they are a different race.
And this pre-dates "PC nonsense" by a number of centuries.
A child that was french and Hungarian was "mixed race". If you were Han Chinese and Vietnamese you were "mixed".
Sorry that it offends your tender modern sensibilities.