This does not deserve a ten in any way, yet the most popular opinion is that it is worth a ten? The art is decent, but the plot is bog standard if not a bit worse. The main character lacks a personality trait that makes him seem like a person and not some kind of self insert and the setting is also pretty boring. It does (for the moment) escape the harem trope but hits pretty much every other cliche for the video game styled fantasy genre without attempting any notable subversions. Even the stupid cooking isekai with monster plants is more creative than this. Also the message seems to be that he wants to beat the demon lord with his own power, and that might have been a bit interesting to watch him slowly build himself up again and become strong enough to beat him through hard work, determination, and the knowledge he already possesses as well as any he learns along the way but WOW a Friggin Cheat Sheet just FALLS INTO HIS LAP? HoW cOnVEniEnT!!! He has everything given to him on a sliver platter but makes this knowledge out to be his own.
You know what he SHOULD do although which he totally won't do?
JUST SHARE THE INFORMATION WITH HIS PARTY TO KILL THE DEMON LORD. That's enough to have them crawling back for his info and also saves the world faster than how he could on his own. Instead, the MC opts for the choice of letting innocent people get slaughtered by monsters while he slowly nurses his emotional boo-boo and slowly gets strong enough to beat the big bad.
Does it sound like I am annoyed? It's because I am annoyed.