So, if I can come in at the final hour and dog pile on the story for anyone who cares and has read this far. Well, why you ask? Well, because this was one of the rare harem-based isekai mangas where the author thought up an in-world justification for MC to have a harem of female characters flocking around the MC. However, for some odd reason, the author was too skittish to commit and I'm not necessarily talking about the seggs, but the author seemed to be invoking classic harem genre tropes where MC target-locks on one of the female characters while evading the advances of the other female characters for the entire story. Not only that, but said female character The Princess, knows that MC can only save her world if he grows his relationship with the other Princesses, but she stubbornly and selfishly wants to keep MC all to herself and will cockblock the other Princesses. As Deoxyribo9 reveals, this lasts up until the final chapters and then the harem stuffs happen more or less off screen. Again, you might be wondering, "Ok, so what?" But the problem is the author purposefully tied MC's strength to his relationship with his harem while forcing MC to stubbornly NOT WANT A HAREM.
So, this starts with potential but becomes infuriating each time that's brought up and the author does bring it up often. Even by way of having MC be obviously weak in the face of enemies because MC didn't grow his strength properly by growing his harem, growing his relationships with them, and training himself properly.