His ban rate has nothing to do with tunneling
It has to do with his insane agency with all the new items, combined with Season 8 BUFFS, and the fact now Bounties give all the gold to the killer.... of which even bad Yi's are never lacking due to their damage kit. He's the easiest champ in the game to get Quad/Pentas on and he gets them early game. And atm he's VERY hard to hit with any kind of CC, and even if you do hit him, he's usually out of it well within enough time to make up the distance/kill you.
He generally no longer has any solo 1v1 counterplay because of how Guinsoo's works. He only has "marginal" success of counterplay as a team.
They are rewarding killers way too much right now and secondary contributors too little.
(Keep i mind they've added 8% attack speed to his starting attack speed because he "no longer got attack speed from when they nerfed
- versus minions."
V8.11 NEW: Now has 8% bonus attack speed at level 1.
V8.3 - 8.11: Alpha strike Mana cost reduced from 70 / 80 / 90 / 100 / 110. to 50 / 55 / 60 / 65 / 70 (ie the largest mana cost reduction in the history of the game for ANY champ)
8.3:
Wuju Style Wuju Style
Bonus true damage increased to 18 / 26 / 34 / 42 / 50 from 14 / 23 / 32 / 41 / 50.
Active bonus AD ratio increased to 35% bonus AD from 25%.
(A ~40% increase in additional AD, + 4 more damage at low levels)
And then there were the late Season 7 Changes which made his kit more troll:
V7.2 NEW EFFECT:** Channeling Meditate pauses the durations of Wuju Style Wuju Style and Highlander Highlander.** (He can literally pause his own ult)
NEW EFFECT: Now grants Master Yi one stack of Double Strike Double Strike per second while channeling. (Gives him an EASY way to charge Guinsoo's)
Season 6 was also all buffs..... more heals on Meditate, more true damage, more Q damage..... but that's reaching too far back.
He literally is more toxic atm to play with than Yasuo...... because of how easy it is for him to reset Q. You have to ALWAYS be with a team, or ALWAYS land CC to remove him from the equation. Which..... you can't do. You have to lane. And if you're laning, Yi excels at diving you. Makes it easy for your opponent laner + Yi to own you and not die on turret dives.
He literally only dies if teams are lucky enough to hit him before Alpha strike hits and ccing him into his post Alpha to erase him.