How hasn't vi been nerfed yet.

Vi has been one of the best junglers for quite some time just like hecarim. I'm not complaining about but it seems they just don't want to do anything to her regardless of her still being top teir for like 4 patches. So far, I've only seen hecarim and ghost nerfs. Shyvana got nerfed and vi was untouched. Why nerf someone who isn't powerful in all elos. Shyvana is good until plat and maybe low diamond at most. I understand arhi is always a top teir champion but it's probably riot hasn't really found a good way to nerf her jack of all trades kit. Not saying she's op af. There's always been things 1000 worse like alpha tf, 99% ban Kassadin, etc. Anyways vi s at a 54% winrate and it's the highest out of anyone for jg. She peels really good for carries. She builds bruiser. She dives backline easily with ult and if your team focuses who ever you ulted and hopefully it's the most valuable enemy champion, you win the teamfight. She can also kill tanks with her q's massive armor shred and ,% max health and it scales with 35% ad. Your basically melee vayne. She has good clears and can play aggressively unlike shyvana who needs lvl 6 to do anything. she has good scaling so she's relevant all game unlike Pantheon and nocturne. I've actually started playing her and I'm doing really good and it's consistent. I've only recently started playing her and I'm doing good. Thats says somthing. So if she's so strong atm, why hasn't she got riots attention yet and how is it shyvana got a nerf and not vi.