I'm curious about why family titles change depending on gender in Korean.

One of the most interesting things about learning Korean is that different words are used depending on gender when calling siblings. When a man calls his older brother, he says '형', and when a woman calls her older brother, she says '오빠'. This seems to imply a three-way relationship that includes not only the relationship between the two people but also the gender of the speaker and the listener. I wonder if there are other fields in Korean where different words are used based on gender like this? Or is this difference limited to family relationships and social titles? Do Korean native speakers consciously make this distinction, or does it happen automatically?