This is far from the worst thing I've ever read, but after a somewhat promising start it falls into just about every trap possible.
The story is, at its core, bog standard isekai trash. Depressed real world loser dies and is reincarnated into a world where all the stuff he wasted his life on in the real world that made him hated/picked on/teased/pitied suddenly makes him a god king. He turns out to have uber powers and is actually the strongest without really trying. Girls fall over themselves to be near him. He rises to top, outclassing anyone and anything in his path. Etc etc.
meanwhile from a story perspective the author has clearly gotten so far up their own ass about their terrible fake rpg mechanics that a lot of the story time is spent explaining those in excruciating detail to the point that it takes away from time that could be spent actually giving us story. So instead we get like 5 pages of infodump about skill trees and unlock criteria and then 1 page that more or less says "and then they did that."
Plus the author can't seem to decide whether the MC is supposed to be a decent person or not. From time to time he has pangs of conscience when necessary, but his rigid commitment to his "I'mma be the best there ever was" goal occasionally makes him come across as somewhat sociopathic and uncaring. It's weird how he flips from being revolted by some ideas and things but then other times just sort of brushes it off like it's beneath him to care.
Toss in that the harem tag is mildly misleading as he seems to harbor absolutely zero romantic feelings for his party members while a couple of them at best display something that could be categorized as excessive devotion as much as could be very obtuse romantic love and there's not a whole lot of personal relationship stuff to carry things.
The secondary characters who aren't the MC are interesting enough to keep me going for now, but I can easily see a future where this drags to the point that I decide just to stick it on hold and poke back in after a dozen more chapters or something.
Its commitment to being more about the sort of stuff that should've just been worldbuilding research rather than story content kind of reminds me of Isekai Nonbiri Nouka where it feels like the author just wants to map out the facts of the world rather than actually tell an engaging story in it.