Ranked AFK Plague in Low ELO's

I'm by no means the best player, but I usually don't die very often, and I'm careful about making sure I'm building correctly and helping out around the map when I can/should, but when I actually try to improve my ELO my matches are mostly determined by the number of AFK players there are. I'm not trying to put the blame away from myself, I'm sure there are many things that I can work on and improve at. I'm not at a skill level where I can solo carry my matches, so the outcome of my matches is really dependent on the whole team being there (surprising, I know). I decided to play my placement matches (Flex only) after 1-2 years of not playing any ranked, and just focusing on improving my gameplay in normal matches. Out of my 10 placement matches, I had 6 afk's in the matches. One of those afk's was on the enemy team, 5 were on mine throughout the 10 matches. When 50% of your matches contain an afk player, isn't that a significant strike to your chances of ranking out of bronze? I know that is controversial, and many players tell me I should be able to win even with AFK's, but that doesn't really happen...

Most of my matches where everyone is there end up being a win; my winrate is 65% in normals, but ranked is much lower because a.) I haven't played as many matches in ranked, and b.) I've lost a larger percentage of the ranked matches. I also notice a significantly higher amount of AFK's when I'm playing in ranked. Don't ask why, but that's how it is. I never see any AFK's or disconnects until I go in to ranked matches.

Can someone tell me how I'm supposed to reach a higher ELO when half of my matches in bronze are determined by afk's, people lagging out, etc? How is ranking out of bronze and silver anything more than luck, when your skill or your KD in a match isn't nearly as significant as missing one or two players? Does anyone have any solutions or methods of getting around this awful part of the game? I feel like in high silver/low gold there are less AFK players and there is more of a chance to play with people who aren't going to DC for early and mid-game, then come back and throw late game...

Again, not saying that I don't have my own things to improve on, because I am in bronze, but I feel like AFK's take a larger toll on a game's outcome than my gameplay not being flawless in the Bronze ELO.

Thanks for your time and any advice that you may have.