I'm honestly mixed on that front. On the one hand, yes, effort is almost always required to become powerful in these stories: you're not just handed an S-class ability all juiced up from the get-go, you have to earn it. But on the other hand, in most of these stories there's also a LOT of luck and innate ability that also factors into the protagonist's success that isn't really acknowledged. It's dangerous to imply to youth that effort = success, because it leads to a few erroneous assumptions, such as: successful people must have worked hard to get to where they are and people who aren't successful must not have tried hard enough, effort is always rewarded eventually, pushing yourself past your limits is something to be praised not avoided, sheer willpower can overcome any handicap, etc. It's a recipe for future disappointment and burnout (or even permanent disability), which seems extra dangerous in cultures that already abuse students and workers with unrealistic expectations for overexertion.