The practical consequence of calling romance the horizon is that the claim stops being testable. If irrigation and safe roads count as romance, then any act of care qualifies, and the argument wins by definition rather than evidence. Yes, romance belongs to civilization; I concede that. But a world where other people can court is not the same as Senku needing a romance subplot. For a lead, that subplot costs pages, tone, and focus. His arc is already emotionally complete through mentorship and shared survival. The other side has shown romance can exist around him, not that centering it improves the story.