Tangent, but I’m really curious what country you’re from that uses the endonym for Göteborg but then also spells the capital of Denmark like Kopenhagen?
I'm born and raised German, and above I mostly used the German ways of writing the town names (stripping the umlaut). Which as it turns out are not the same way you'd write it in english, interesting!
I'm pretty certain all languages do that. It's fairly common to bastardize/assimilate the names of important cities and/or trade hubs into the local language, but leave smaller names unchanged. That's why it's Milano/Milan, Venezia/Venice but Cagliari doesn't have an americanized name; that's why it's Moskva/Moscow but still Irkutsk; Warszawa/Warsaw, Gdansk/Danzig (in German), Katowice/Kattowitz (in German), etc.