Yes I'm in Bronze but I have to admit, it's usually not my own fault when we lose, as arrogant as it may sound, you can look up my match history. I often get highest vision score, regularily I'm the only one in team buying Control Wards except sometimes rarely our support do but I always do. I get feeders often, AFK not so often but feeders often and flamers tilting after first blood. I sometimes make misstakes for sure but the point is I usually try to guide my team by placing wards in case of ganks or simply pinging them when it's obvious our team is on his or their way but nope, let's get these last minions so that we can die. I've lost a lot of promos due to this. Also another fact, when I duo queue it goes TONS better, I win probaly 3 times more but even then I sometimes have feeders or afk.
Like yesterday I got a Lee Sin jungler when my premade friend forgot one SS he said %%%% YOU I'm feeding MF (the enemy adc). I said please don't it was just a mistake but he didn't give a single %%%% so he went into their turret and stood there. I asked enemy team NOT to attack him because he is trolling and inting but they said "who cares it's ranked". So he went 0/12.
After that game, we duo'd again and this time we got Teemo Top AFK so we lost hard. Yet again I didn't even feed even though we were far outnumbered with everything.