If a hoagie or hero is a sandwich, then it is only logical that a hotdog is also a sandwich.
EDIT: Since my criteria here has been cited by others and this comment, as initially presented, contributes very little to the discussion, I am amending this comment with the following information: Based on Ken Burns’ Baseball documentary (at least my memory of it; been a few years), the hot dog has its genesis with guys selling food outside of a baseball park. They were selling sausages that were coiled, and served on a bun. The buns ran out and so they grabbed some Italian bread sold nearby, cutting the sausages and laying them in the bread, sliced sideways. This posits that the foundational concept of the hotdog was a conventional sandwich.
If a hoagie or hero is a sandwich, then it is only logical that a hotdog is also a sandwich.
EDIT: Since my criteria here has been cited by others and this comment, as initially presented, contributes very little to the discussion, I am amending this comment with the following information: Based on Ken Burns’ Baseball documentary (at least my memory of it; been a few years), the hot dog has its genesis with guys selling food outside of a baseball park. They were selling sausages that were coiled, and served on a bun. The buns ran out and so they grabbed some Italian bread sold nearby, cutting the sausages and laying them in the bread, sliced sideways. This posits that the foundational concept of the hotdog was a conventional sandwich.