First, I would like to say that I have no intention of comparing Kenja no Mago to other animes. I want to talk about it as Kenja no Mago not ,,other isekai''.
I want to say that I gave it that rating because it fulfilled my expectations which were: OP MC, a world where magic exists, and a big portion of humor. A lot of people here on MAL are talking about typical isekai cliché where MC dies in the first episode without any personality. I agree that viewers won't get a chance to know more about ,,MC from Earth'', but I don't think it's necessary because Shin doesn't bring almost any inventions from Earth to the new world. I think that anime doesn't need to be always that much original, I watch anime because I want to ,,have fun'' and I got that feeling from Kenja no Mago so I don't have any reason to call unoriginal anime ,,bad anime''. I really enjoyed it because I got everything I wanted and there wasn't any moment when I wasn't having fun.
Thank you for your time.