@thatfinefellow No shit it's the "epitome of the isekai genre".
They say this series is basically the trope definer and the grandfather of the entire genre.
That said, to identify where a trope comes from and to pretend it implicitly address character psychology are two complete separate things.
Your original comment was about how "sad" it is that he can't live in the "real world".
For one, in the context of this story this world from his perspective is every bit as "real" as the previous one. He's not living it as a videogame, but as an entire new incarnation.
Beside that, given his personal experience with the previous life it's beyond obtuse to pretend it's surprising that he doesn't feel any particular urge to "go back" (assuming that would be even an option at all):