The most prominent exonyms are of cities like Paris, London, Moscow or Beijing.
I.e., places culturally and historically significant enough that older historical pronunciations have become ossified in foreign languages.
English having a "Prague" spelling means the name of the city was important enough to have entered the English language back in the day when English was still borrowing heavily from French.
Um. Beijing's not the exonym. Like, maybe this reveals that I'm ancient at this point, but I remember it being Peking at least the first few years of school.
