This is an attractive waterfall, and your slow shutter speed produced a nice blur.
This is a picture that is just screaming "polarize me". There are highlights on many wet rocks that the polarizer will turn off. The rocks will then become a darker reddish brown which will accentuate the waterfall. The polarizer will also saturate the green color of the leaves and moss.
There are some bare branches above the waterfall that distract from the waterfall. As much as I like the bit of blue sky in the photo, I think your photo would be enhanced by cropping off just enough at the top to eliminate those bare branches.
I am not upset by the perspective of shooting up. After all this is what a waterfall looks like when you stand at the base. You captured reality. This is also a very bold perspective which I find pleasing. It has an up close and personal feel. If it were possible to reach a perspective halfway up, I would also attempt to get there for the different perspective.
Canon does make several tilt/shift L-series lenses which can be used for perspective control. I own the 24mm and 90mm, and they are very helpful with photographing architecture from street level, restoring converging vertical lines back to parallel. However, they are bulky, expensive, and manual focus only. I don't pack them into the wilderness unless there is a very compelling reason to bring them. I would not bring them for this type of photo.