Why are people complaining about autofill in 2019?
If you don't at least have a reasonable knowledge of every role, let alone capability to play all 5, you have no business playing ranked and bitching when you get autofilled.
And if you have teammates that get autofilled, who aren't intelligent enough on their own to learn the roles they get, offer them yours. because after this post you're going to go learn to play every role, and stop being a vagina about it already, right?