Right now, Autofill is one of the most major problems in ranked, not the system itself though. But rather the players that get ''autofilled''
* There are people that get autofilled into roles that they don't really play which is a problem that leads to fed enemies.
* Then you have the ''autofilled'' support player which will start trolling, again leading to a 99% chance of defeat.
* And the most common type of ''autofillers'' that just ignore their autofilled role and will go to a lane of their own preference, leading to (99% of time) a defeat also.
* And there are the autofilled people that will pick their main champ for their autofilled role. Yasuo isn't a good support, understand it pls.
So whereas Riots intention was to make the queue times shorter (which indeed became much more shorter) they have also created a ''clown fiesta'' that will happen in a lot of ranked games.
Please Riot, improve your system (for example by seeing how well player performs in each role and autofilling them in roles they perform well with) or just remove it, I rather would wait 10 mins for a game than get an instant defeat by an autofeeder.