To be honest, almost every important character/creature in Skyrim is nerf. In the lore, the Fus-Ro-Dah shout can destroy entire towns and even cause Earthquakes, The Dragonborn is super nerfed, Dragons are weaker than Mammoths/trolls and Alduin is only slightly stronger than regular dragons. In the lore, Dragons are known as literal Gods and only people like the Dragonborn and extremely powerful mages could take them on.