Without sufficient strength, one lacks the means to survive in this world; survival of the fittest is the law of this cruel world.
This is especially apparent for mercenaries, as their income directly corresponds to their strength.
Even when dealing with equally powerful monsters, the more formidable the mercenary, the more money he can demand from his employer.
On the other hand, the weaker they are, the more they are underestimated and overlooked.
Some employers might even worry about them dying in the wilderness and refuse to pay their deposit, forcing them to face dangerous magical beasts.
Everyone knows that life and death are predetermined, and wealth and honour are bestowed by heaven; the majority of people opt to accept their fate.
However, Luna didn't see it that way. Even though she was weak and not very powerful, she refused to admit defeat so easily.
Some things could only be obtained through personal effort. Otherwise, they were impossible to obtain.