I think the picture looks fine.
It is rarely needed to get pictures sharper than this. Viewing at 100% would be equivalent to printing in a size more than a meter long. Hardly anyone does that anymore, and if someone does, we don't put our nose on it and complain one of the leaves could be sharper.
Expecting perfectly sharp results at 100% will always leave you dissapointed. It is simply not possible because 75% of what you are seeing is made up and does not really exist. Any camera that can take color pictures has something like a Bayer filter. This filter filters out everything except one primary color per pixel (this statement is somewhat simplified, but the filter does block most of the light). Your camera has algorithms that try to recreate this information, but there is a lot of guessing involved. There will always be imperfections, called artifacts. Especially around sharp edges this leaves unsharpness.
It is often better to focus on other areas than optimising sharpness, but if you want to improve the sharpness, you could try the following.
1) Shoot at your lens's optimum aperture, this is usually around 4.5. You can often find this on the internet. At F/14 diffraction starts to play a significant role.
2) Check your processing sharpness setting. Pictures are made unsharp in most profiles to make them look more smooth.
3) Use a faster shutterspeed. The 1/F rule comes from the old days when people said that a 600x400 pixel television was very sharp. If you want maximum sharpness at a 100% on a modern camera you need to go much faster.
4) Buy better equipment. If you look at 100% everything matters. I would not recommend this though. My photo's started improving many times faster when I realized that learning about the artistic side photography was a much better way to spent my time than reading reviews and thinking about new stuff to buy. You will always find limitations in your equipment if you look for it, but they are rarely a big issue in normal use.