@Kanami-chan
Thing is, you're taking Akagi's words too literally. He said that to him because he saw him struggling with his self esteem ("you don't know what's like to be depressed" and such). Hiro doesn't have Akagi's natural talent and he lacked the experience that Ten or Harada have, but he is not Pen-chan. He was always promising: read his match against Ken again where he analyzes the tiles available and gambles on the uradora, or when he carefully executes his plan to betray Washio and steal his place in the final match. That's not what a third-rate player would do. Akagi used that word exactly because Hiro is obsessed with success and feels like trash whenever he makes a mistake, it's such a strong fear that he even abandons his dreams and settles for a job he dislikes. What Akagi is criticizing is that he has given up on his love for mahjong because he's convinced he's always going to be a loser. In another scene, he says to him "don't decide that you're going to lose". His final speech is something similar: he wants him to do what he loves without caring about "failure" or "success" (linked to what he previously said to Harada). I believe that Hiro already had what you need to become a strong player, but he had to get over his fear of never being good enough, which is why I don't see any issues with HERO.