Imagine saying "Are you giving up" right at your crush's face, aaand then refusing to cheer her up lmao, that would make any woman cry. Is that chad behavior tho? If you win I give you blank space is just a trivial lover's game and following that to the letter is kinda autistic. Nagatoro is consciously aware of her capabilities. Who is he to keep putting himself as the prize at something so personal? Just be there for her bro.
Now she has to win the match, it can not be any other way, narratively speaking.