So.... Buff Teemo?
Top team in the region takes it against one of the worst teams. Casters are talking about how they would never pick it unless it was a game that completely didn't matter to their standing AND was a joke, because picking that champ will trash their chance to win. The normally dominant team gets completely crushed.
Now, some people will say that one game doesn't prove anything, but it really looks like the casters and conventional wisdom are right, you really can't win against competent opponents while having Teemo on your team.
Memes about hating him aside, is there a sound game design reason why he shouldn't have a reasonable path to success comparable to other champions? Despite his ult being literally toxic it's not as metaphorically toxic as, say, old Poppy ult.