I almost always play solo queue, and i noticed several categories of games :
1/ You start your laning nicely, maybe get a couple kills, while another lane feeds the enemy. Around the time you take down the first tower, the fed champions come and get some more kills from you or your lane partner. Then the team fights start, you all drop like flies, often from lack of team play. You lose the match.
2/ You hold your lane while your team gets fed on another lane. You win the team fights, you get their towers down, you win. It feels too easy.
3/ Laning is balanced, your team plays too offensively, often soloing, not playing as a team. They get killed. You lose.
4/ Laning is balanced, you manage to rack enough gold and xp from farming and kills, and your team doesnt die too often. Once you reach your engame gear, you obliterate any opposition. You win.
In the end, my problem is that even if you play very well, it mostly depends on what the game gave you as team partners and opponents, and you won't make much of a difference. Even if you play badly, your team will win if the matchmaker decided that you needed more wins. I just had a match where we all agreed that our team composition was pure crap, and theirs was actually pretty good, but we still won because the matchmaker threw us some noobs to balance our win/loss ratio.