The differences between good stories and the ones that kind of fade over time, is the premise, the writing quality, and the plot. The premise is good, the writing quality acceptable at most times, but the plot is a jumbled mess.
The MC stumbles into everything. Every positive action the MC takes is almost always entirely detrimental to himself and others, and it is the actions of everyone around him that save his hide.
1) Takes a party of well-known asshole nobles willing to overpay for his services. This should have given him red flags. They treat him like trash and even give him items during this period, signalling their complete devaluing of his existence. Mimic joins and saves him.
2) Calls out to adventuring team that a dungeon is resetting that is OBVIOUSLY actively looking for him and his party that just died. The sidekick saves him from the party he warned trying to take him.
3) Decides to go back to the city for his admittedly small life savings inside the city who’s son you just murdered that runs the place. Hitches a ride on a carriage underneath the duke that is also in town for probably nefarious purposes and still goes in anyway. Sidekick has a magical seed that allows the infiltration into the city.
4) Gets caught by the noble’s father (Im sorry this one of the things that make zero sense, he would have had a subordinate do this. The duke is in town and would absolutely be entertaining him, even if it is his favorite son) in his own room in town. Proceeds to almost bungle a lying detecting McGuffin. Saved by the noble himself for literally zero reason, other than the obvious answer that I cant support being that he noticed the mimic.
5) IGNORES the Duke’s obvious wanting him to join a cattle call audition for a scout in favor of exiting the city with two different groups following him, obviously trying to either kill or capture him. Saved by another hero for seemingly no reason.
All this to say, having a MC make mistakes is fine. They can’t know the particulars of the world in fine enough detail, but either give the MC the tools to escape or give him consequences for his actions. So far, he has just blindly survived where he should have died AND is being rude calling his only real support a monster: the mimic.