Shark skin is rough is one direction and smooth in the other. This allows them to get friction with the water to drive themselves forward, but the glide through the water for efficient travel.
Few people have gotten close enough to a shark to pet it. If you could run your hand from a shark’s head to its tail—not that you should—it would feel smooth, almost like suede. Reverse direction and it’s rough like sandpaper. Viewed under a microscope, shark skin is composed of ribbed, dragonesque scales layered over each other like shingles on a roof. These structures, called dermal denticles, are more like teeth than skin
The same is true about sharks.
Quite the opposite:
The idea was copied into competitive swim suits.
Nah, you’re wrong. Sharks are silky smooth in all directions.
https://www.smithsonianmag.com/innovation/shark-skin-inspired-materials-have-a-long-way-to-go-before-they-work-like-the-real-thing-180980973/
The link you posted says sharks are smooth as the finest silk in every direction.