You might be wondering why so many people rate this a 10 and I don't... it's probably the same reason SAO became popular and isekai has become such a brain dead genre: it has a great power fantasy element that, even if not the best, still keeps people's attention.
And to be clear, the power fantasy is excellent... too excellent, in fact. Because no one except for the main character can be competent in fighting the toughest opponents; not even for more than a few minutes. It's not noticeable right away, but once it's noticed, it only gets worse and worse and worse. It's great to be great... but to not have any friendly people capable of fending for themselves?
It's such a pathetic world that I eventually stopped caring for it. And knowing the main character would eventually overcome everything... well, there were no stakes remaining that I was interested in.
Then I read the manhwa to its completion and... what a terrible ending. Like, imagine ripping out the fantasy elements from your fantasy world? Technically they still exist, but it feels like such a copout. It's like the author's imagination just couldn't see any further ahead and so they ended up hitting the reset button.
A few of the after stories do somewhat make up for how bad that ending was, but they, too, feel very muted. It seems the emotional aspects are neglected if there isn't a fight scene.
And don't get me started on how bad Jinwoo's son, Mary-Sue—I mean... what was his name again? Oh, Gary-Stu. So a few chapters show Gary doing what his dad did... at 4 or 5 times the speed. It steals away the meaning of Jinwoo's struggle from the original story.
There are many great parts, but they ultimately get eaten out from the bad ending and the worst parts of the after stories.