When people speaking one language encounter another people, then the first group will only refer to the second group by their endonym if they respect the second group’s autonomy and identity. Their first instinct is just to call them by whatever details might distinguish them (“Netherlands” because the land is pretty close to sea level), or even by what they might say often (the somewhat derogatory “gook” comes from when American soldiers heard Koreans say “Miguk” which is “America” in Korean; also, I think there are some Indigenous Americans whose English names were simply their language’s translation of “I don’t understand what you are saying”, but I can’t remember what groups).
When people speaking one language encounter another people, then the first group will only refer to the second group by their endonym if they respect the second group’s autonomy and identity. Their first instinct is just to call them by whatever details might distinguish them (“Netherlands” because the land is pretty close to sea level), or even by what they might say often (the somewhat derogatory “gook” comes from when American soldiers heard Koreans say “Miguk” which is “America” in Korean; also, I think there are some Indigenous Americans whose English names were simply their language’s translation of “I don’t understand what you are saying”, but I can’t remember what groups).