And in this case specifically, prestige is a French word (pretty clear given the pronunciation) that's also been imported into several European languages.
When discussing English, the fact that a word is imported from any language should not matter, as English is a thief language.French however is VERY present in English, since about 1066 anyway. I've been told about half of our words in English have French roots. Further many of the "fancy words" are of French origin, due to the simple fact that the nobles spoke french, and that connotation still exists in the language.
Short version: lots of french words are in English, why does this one example warrant mention.
Short version: lots of french words are in English, why does this one example warrant mention.