I think it's like how most of these isekai stories have cookie cutter plots. You get summoned to another world where the humans are in danger because of the demon king and want you to defeat it. Like they were designed with a script. The gods prob got it in their heads that there is a certain way the story needs to play out and they don't like that he isn't following what they believe to be the correct storyline.
I dunno why the gods have this system in place to begin with. I doubt there's any real reason for it. Prob just the gods' way of entertaining themselves. Unless they too have some kinda even more powerful being controlling them. They want their story done a certain way and when he doesn't do it that way they make him repeat it. cause they're a buncha douches.
I actually really like this, but am i the only one that doesn't understand the plot? Like for what reason does the MC have to go through this... Supposedly there are parallel worlds where each one has a hero. So why do the "gods" keep forcing him to go back and do it again, when there are so many other worlds. If it's so "he can live a good life on earth afterwards" that's shit since its not like he asked to go to Fantasia and they already made him live out a 10 year life anyways the first round. You think he wants to go back to being however old he was (middle school maybe?) after living 10 extra years???