Can’t speak of other languages, but in German anyway the sentence is exactly the same. “Ich bin zuhause” meaning word-for-word “I am home”. Same issue, normally a location would have a preposition and an article. Reasoning is also the same as in english, “home” and “zuhause” are not a location but a state in this case.
True. I was more going on the idea of OP that it must confuse english learners. I often feel people who only know one language tend to forget that most latin languages tend to have similar quirks, often making such quirks in a foreign language rather natural.