no.
Even without the active, youmu's is too good on Yi. The armor penetration it gives is way too important, and the cooldown reduction is nice. Also Attack damage. Also crit chance. It almost has everything yi needs. Just learn to use the active.
Attacking fast and getting crits won't mean much if you can't get through their armor, and if you're not doing any damage to begin with.
Even without the active, youmu's is too good on Yi. The armor penetration it gives is way too important, and the cooldown reduction is nice. Also Attack damage. Also crit chance. It almost has everything yi needs. Just learn to use the active.
Attacking fast and getting crits won't mean much if you can't get through their armor, and if you're not doing any damage to begin with.