Case in point, I just played a game with a yi that went 0/8/1, doing his placements and he lost all 3 of the games so far, hard feeding in each of them. My MMR is low gold to high silver. How come the enemy team isn't guinea pigging their elo with a similar "wildcard" teammate?
This proves to me I can't trust the matchmaking system. If I had op.gg'd my team before the match I would have sensibly dodged on seeing this guy. The fact that doing this is such a huge advantage, it's almost like the new version of blocking the first spawn of creeps so the enemy's creeps are closer to your tower (which was justly removed). The same is true with teammate information, if you don't make tactical dodges based on it then you're at a disadvantage.
I'm not going to ask Riot to improve their matchmaking. I honestly think they're doing the best they can already. But can Riot just partner up with op.gg and let me access my team's information in the client? This way I don't have to go through the hassle of copy/pasting my teammates into the search before every game. I think it would be more fair for everyone that way and not just the people who already exploit this.