Sivir has one the lowest play rates, and at the same time one of the lowests win rates of all adcs
Most of the time when we see a champion with low play rate (2.42 for kayle) they have a pretty high win rate (53%) this is because of only mains or people who have invested time onto the champion playing it. Sivir, even after her items being buffed is still struggling, has a average 49.51% win rate and 2.54% in plat+ soloq. and its not surprising cause her recent nerfs ( in season 6) crippled her Dps..and she already had a medicore utility (nerfs in season 5) Shes in a weird spot...every other adc can do what she can but twice as better. Need utility pick ashe. Need aoe crits? pick twitch or jinx.
Heck, her last set of nerfs were not even justified.. because as she got nerfed, armor pen lucian/MF just started to get popular, giving her a weak early game, even more rough.
I think undo'in the nerfs to her W and R should be enough.
or
because they are hard engage that will either always net a kill or force a flash with their Ult/R abilitys, a team movement speed buff can be used with the likes of
and they still have hard engage with the marksman, just good follow up with a