LoR: Why does Tryndamere have Fearsome but not Darius?

Darius is one of the few champions in the game with fear in his kit in League of Legends. Tryndamere doesn't. Fear and fearsome isn't exactly the same but its close enough. Tryndamere seems to outclass Darius just because he has a "free heal" when leveling up and he has ridiculous defense with his high attack. They should get rid of Tryndamere's fearsome and put it on Darius instead in Legends of Runeterra imo. It's a lot easier to deal with Darius since he has low health, I think he needs a little bit more edge to him. Darius is lower cost mana, but Tryndamere just seems a lot more oppressive for being only two more mana.