One of the big trees has a shape similar to the leaning rock tower. Does it need to be removed?
All that texture in the dark green trees could be a distraction. What if you just painted it all as a simple green shape, with no texture at all? What about removing all the trees?
The silhouetted hills just across the water are very dark. Should they be lighter? Should they be dark brown instead of black? And what about the pointy saw teeth along the top edge of the hills? Would it be better to have fewer of them, like, none, for example?
Too many shapes!
Some of them have got to go. Big ones, little ones? Near? Far?
How will you decide what you can afford to edit out and what you ought to keep?
The best way to see whether something belongs in the scene is to leave it out. If you don't miss it, it's optional.