Really simple tip to help with afks and dcs in ranked
Play ranked at a time when people are less likely to leave. Have a friend to duo q with, especially at low elo.
What do i mean by that?
Simple, think about the time and day you are playing the game. A lot more people are likely to leave on a friday/saturday as they probably have some other plans as well and depending on timing might have to leave in the middle of a game.
If you rage about 8 afkers in a row, honestly what time are you playing at? Play on a tuesday night outside of normal dinner hours when people have time to sit down in front of their computers and it'll make a difference. Obviously it might not be possible for you to play at this time but make an honest assessment about the time that you play and look for more "normal" hours.
Duo q helps immensely with afks. Im not talking about duoing with completely random strangers all the time as they may or may not care to stick around in a losing game. If you know you are not going to afk and you know your friend wont either that gives you a huge advantage. You don't need to be some yolo q grind star. You and a buddy who are both not going to afk gives you control over 40% of your teams intentional quitting vs 20% (incredibly difficult math with intentional being the key word)
Just some fairly simple advice that will maybe give you a bit more control over your games. Still cant do much about people raging but that is a different issue.