I don’t think we actually disagree, it’s just that you’re talking about ought while I’m talking about is. I see no reason not to allow sneak attack with handaxes (or clubs, or Spears, or... pick a weapon, really), nor do I see a reason not to allow booming blade or green flame blade with unarmed strikes. I’m saying the reason those things aren’t allowed by the rules as written is that the people who wrote the rules had something specific in mind for what those features represented in the fiction, and that didn’t include using them with the weapons (or lack of weapons) in question.