He has a small gap closer he does alot of dmg at like lv 6 i think (Im b3 sorry if this is wrong) he has alot of ms duelist potential he can fight 2v2 incase of a counter gank and with red buff and his attack speed he has them slowed like perm tons of as and slows them and ms to catch up
ChaddyFantome4 votesbecause he is a late scaling champ and has no CC. All he brings to ganks is damage.
Jbels1 votesMostly because he's so squishy early. If you get counterganked, chances are you're going to die in the 2v2. Personally I prefer Warwick over Yi. That's not to say there aren't rank 7 Yi gods out there that make the champion a nightmare to deal with
Need Gold 4 Tent1 votessometimes you don't know what they're picking and your comp only has a lux Q, singed E and ekko W as hard cc. then the enemy yi proceeds to get fed and deletes the entire team in 5 seconds.
justblindpickthings
i picked leona the next game...
ScissorsNstuff1 voteshe isn't, he's just average
thecowley1 votesLike most things low elo, we dont plan our team comps enough. Its why no mater what role i take, i try to be at least a little tanky. IM b4 myself, and its super annoying to see every one else on the team o hyper carries while im sup leo/ali and only tank on team.
Chaos Milk Tea1 votesHe has no crowd control. Sure he can reach his target, but he can't stop them from running back to their tower. He needs the lane partner to hold them down for him so that he can deal his damage. That way he can save the gap closer for when they are about to escape.
Alex h87211 votesI can think of a few reasons, especially early (his ganks get better at 6 but still not THAT great)
Yi brings consistent damage rather than burst, so he has less chance to secure the kill than say a Khazix who can Leap/voidspike/AA>Q dead a squishy.
No CC, especially without redbuff your ally laner you are ganking for needs to help lock down the gank target.
Gets shutdown easily by good peel, for example if a 
saves her bubble for after you Q to gapclose (bonus points if she stuns you under turret) you are probably gonna die if the enemy laner knows what theyre doing. Once yi gets 
>
this isn't nearly as bad but that is most likely a 4th item (including boots).
Yi is very item dependent, as with any hyper-carry champ his damage scales far better from items than base levels and your damage is going to be very subpar until at least Bloodrazor enchant.
Edit: But these factors also allow a yi with a team that understands Yi to do very well in mid-late game. If Yi's team initiates for him, forces the enemy team to blow their hard CC abilities, yi can ult>Q into the chaos to kill a squishy/extend the ult duration, get Q/E Cooldown resets, use to escape any CC that the enemy saved for him, W also helps to stay alive/sustain, and keep pumping out his high sustained damage.
YoungSirJ0ey1 votesHe's an item reliant carry. Early, he does too little damage, and doesn't attack fast enough to get resets on his Q, meaning he can't stick to people. His ult does solve some of these problems, but getting to level 6 as Yi takes a good while. It's the same reason why you don't play Kassadin jungle.
