I actually have the same thoughts as you, cringey and with so much plot holes. And I did finish it but I can honestly say that what you are feeling will continue to be or get worse as the story progresses.
The main point I have of this drama, which probably is how you see it too is that the The characterization of MC is definitely suspect. Him being a mafia comes out in specific scenes to suit the picture. He does mafia things to prove a point, and then makes him so much un-mafia things all through out the drama. They don't even try to explain much how the switch happens, it just does. He definitely has the Hero halo protection with him being slick and awesome all the time, whether he is doing mafia things, or being approachable, or being badass against the babel group.
I think you and I have a different expectation of what to expect in the mafia would be. this drama definitely did not fulfil that.
But I do see were the others are coming from. I think for other viewers they see an anti-hero to really root for. He is cool and he does kinda become robin hood-esque. Plus the narrative does move fast with regards to who is who and what is the issue and problem at hand, thus no boring parts.
and It does have a so many narrative lines that was tackled that the story was just moving and moving --- from the mafia narrative, to the gold issue, to the intertest and protection of the residents, to the fight for justice for the killed people, to the babel group and their legal issues, then the chaebol issues, and towards the end finding the truth of the psycho and getting him in jail. It was a lot, plus most the characters were pretty funny and interesting.
That said, I can say it was now for me. just doesn't jibe for me. The MC just feels inconsistent and with too much Hero Halo...
Lastly, I just want to point out, that what replied was totally uncalled for. These people have gladly taken their time to help you out and answer your question. Written words usually lack emotional syntax, so you need to probably think twice before posting such words next time.