am I the only one who thinks that Ben is kinda annoying😭?

He is but I guess it stems from him being the only person in the Prince's corner. No matter how much Eckhart shows he'll support the Prince to ascend the throne and serve as his vassal, the Prince isn't really deemed competent. So it most likely will fall onto Eckhart's shoulder to ascend the throne is the thought procesd of most. The Prince being mistreated and only treated as Prince in name only be it in or outside the Palace is probably a huge frustration for him. All he can do is run is mouth and express dissatisfaction so he does exactly that.