Thanks for your thoughts on the game.
Rest-assured though, the plot is centered around the MC gradually developing into a "real" hero, but he'll have to learn the hard way on a lot of things. As with many things in life, direct experience is the most bitter teacher for those who previously failed to develop themselves. And even then, some of his mentors/love interests have different ideas on what an ideal hero should be.
The MC's background is indeed meant to be a zoomer who spends too much time online, unable to hold a job for long. No doubt if the world had not ended in a ball of nuclear fire, then joining the military might have been his last option left to survive given his circumstances.
For now, he leans on luck, his status on being someone from Earth, his odd subtle divine powers, and his companions. In the distant future, that will shift more and more.