-MC starts the game 2-3 days after it was already released, meaning other ppl had 2-3 days of a headstart compared to him and yet he is somehow the first ever person to finish "beginner village" and trigger update of the game. So at this point you look at this and are like- heh, MC is so godly OP, there is no way in hell that other ppl can catch up to him.
-MC is soloing boss that is more than twice of his level (MC was around level 12-13, boss was said to be above level 40, since he dropped level 40 sword). He does it effortlessly... He levels up by grinding mobs that are also near 10 levels higher than him, narrator keep on describing how noone else is able to do that. We get it even more now, our MC is godlike character that cant be ever compared to other players.
-Now the best part! MC joins a guild, sure, why not? And in that guild there are magically a bunch of ppl who are lvl 14, while our godly MC is only lvl 15 himself. How? How is it possible for them to be so high level if our MC was first ever person to reach lvl 10 and he keeps on grinding on mobs and bosses that are impossible to kill for anyone else? How is this supposed to be logical? Those people are also nowhere near as skilled as MC so how they got to this levels so fast?
So... If you want to read this turn off your thinking. Godly MC is soloing bosses way more than twice his level and I bet he will keep on doing this while a bunch of "normal" (highly skilled but not "godly") players will be somehow able to keep their leveling speed near his.
MC is making decisions without any planning ahead. He kept on telling how he must keep his powers hidden till he is sufficiently strong and yet few chapters later goes ahead and becomes known to the whole world as one of the strongest fluxers ever. There was no real reason for that, just because he wanted to get some items...
The most annoying things happened in few last chapters. MC pulled out of nowhere ultrastrong artifact that saves the day- sure, why not you may ask? Yes, having it is not the problem, problem is the fact that it appears out of nowhere, 0 foreshadowing or explaining before that that our hero have ever done anything to get that item. It just appears and then author proceeds to explain how MC acquired it one night earlier.