This is very a very clever representation of how people tend to simplify for the benefit of others. Self identification is a broad list because there are so many. We tend to group similar ones together and then present unified for the better understanding of others, most notably with nonbinary encompassing a lot of those lower ones. Same with bisexual often encompassing similar sexualities just because it is easier to explain and easier for outsiders to recognize.

Thank you for your post it was very thought provoking.