There is absolutely no conflict or obstacle in this story that gives readers a sense of real suspense. It's hard to experience that 'worry' for how things will turn out when there was never a single doubt from either the writer's standpoint or the character's own view of their eventual success. Every single conflict is resolved swiftly and beautifully by the MC, he doesn't even bat an eyelash in worry. Even when he is being wronged, he doesn't show anger, just shakes his head, sighs, and then turns things around so he comes out on top.
This lack of struggle and lack of the MC or ML taking any threats seriously makes it so that I, as a reader, was equally unable to become invested in the storyline. From start to finish, there was only a smooth ascent - the conflicts along the way were too small to even be described as molehills. Every single person trying to stand in the MC's way were fodder characters with no actual strength and an inflated sense of their own value. There was not a single competent villain character in the entire novel.
The lack of real struggle also hampers character growth in the story, and I would argue there was very little and possibly none at all for the MC and ML. From start to finish there is only competence and complete self-assurance, no "can he?" but only a "when will he?" win. In their relationship with each other, they fell into roles easily that never had to shift again. Even with MC's only 'real' problem in being a bad actor, there are no unpleasant consequences and he rather smoothly improves while winning the good regard of those around him. There was no learning or change, only (a) high-handed, overpowered god character (s), which, if you enjoy just reading your mains effortlessly plowing everyone over because they are and always will be the unchallenged kings of the throne, then I guess this wouldn't be a con for you.