@AlmondMagnum
Contextually, I agree with you. They obviously couldn't have gotten that way without hard work and training. However, this isn't about them and never will be. And putting in your own lore only gets you so far. These stories are simple for ease.
You see most antagonists in these stories have always been that strong. Even on the rare occurrence of a flashback, it's typically a, "no one has ever stood against me, so why now?" Type of plot. It becomes less about flipping-the-script and more of a moral like, "don't be an egotistical prick." Which of course is usually their downfall. They looked down on the protagonist and didnt take them seriously.
This, of course, changes should the author have other goals for said antagonist, usually being a redemption and subsequent moving to 'protagonist party'.
TLR you're right, but also not. It's weird when it comes to manhua...
EDIT: Just realized I could have made a, "That's how Manhua works" joke... I've failed the memes...