I don’t actually think there’s anything missing and I don’t think this photo needs a focal point. I think the graphic yet natural tangle is the subject, so no single element in the photo needs to dominate. No reason it shouldn’t be busy. A couple of things I notice that might be causing you to feel the way you do. The centered horizon line may be at odds with the energy (and kinesthesia) of the trees and their reflections. The similar tonalities of the trees above and below may also be adding to your feelings. If you did want more of a subject, there’s a natural one just to the left of center, a kind of oval-shaped hole created by branches and reflections. Also, some selective dodging and burning might emphasize the depth inherent in the scene which the photo may not yet be fully realizing. Regardless, I like looking at this.