Mine is kind of two parts:
1.) My sketches are usually too messy to use as my finalized line art but then I also feel like my sketches are closer to the general style/aesthetic that I'm looking for usually compared to my inks/lineart... it always feels like something gets lost in that stage, and I haven't been able to find a good solution yet (either sketching cleaner or improving my lining technique seems like the two obvious answers... working on both lol)
2.) Part of the above problem might be partially because i just don't like doing the inking/lineart step... like at all lmao. It's like the one step out of the whole process that I feel like I do out of necessity rather than enjoying doing it. Sketching, Coloring, Lettering, Effects... all of those things I like a lot. Linework is bleh to me.