My weakness is I can't make anything that's just simple. That sounds like a humble-brag, but it's not, it's a legit problem and frustration with my work, because complex stories with deep lore aren't intrinsically better, and some of my absolute favourite comics are actually very simple and straightforward in concept, but the content itself is really good, like say "Azumanga Daioh" which is just "some girls are at a generic Japanese high school and they say funny stuff".
As an example, I tried to write a vampire lesbian romance novel. Straightforward concept, it should be "ordinary woman meets sexy, dangerous seeming vampire with heart of gold, then they must spend time together to overcome a problem and while doing so, they fall in love."
But as soon as I started thinking about vampires, my brain was off down this rabbit hole of vampire lore, twists and turns the story could take, and I ended up with an overcomplicated story with too many characters that wanted to devote so much time to this complex vampire lore and the difficulties of overcoming the big bad that it wasn't really a romance story any more. 
I honestly do wish I could just make something that's simple, to the point and easy to sell by not getting distracted by intricacies and then having them eclipse everything else to the detriment of narrative and genre clarity, it'd make my work a lot more accessible (and profitable).