"One who relies on solely on skills has no right to call themselves strong. It's through relentless training, enough to surpass rivals and even stronger foes, that one can rise to the very top"
That's literally what skills are though. Granted, in this context, 'skills' are abilities. But considering MC needs to train in order to learn those skills, that's like saying that someone didn't beat Elden Ring because they wore armor to beat the final boss.