Auto-fill greatly hurts league more than it helps
Autofill was designed to reduce queue times by essentially forcing somebody to play a role that was needed to fill out a team comp. However, not only does it fail to save time, it frustrates people and passively causes them to play worse.
Autofill attacks you on a psychological level before you even get into queue, and continues to do so up until before you get into game.
The fact that you can see it there, letting you know that it exists and that there is a chance you will be filled to a role you don't play, don't play well, don't want to play, is a constant tilter. When you get into game and you got the role you want, the relief is alright, but then somebody dodges (another issues that Riot has yet to address because they're too chickenshit to give incentive to not dodge / meaningful punishment for doing so) and now you're stuck with a role you didn't want to play in the first place.
You wanted to try out a new champion to add to your jungle pool, or a new strat for your main that you've heard is promising. No. More than likely, you just got shoved into support even though it isn't even your fault that somebody else dodged. You got punished for something bad that somebody else did, and now you're tilted. Now you either face what you know is most likely going to be a miserable experience where you'll probably get flamed by the adc and the rest of your team because despite trying your best, you're just not as good as an actual support main. Why the hell should this even be happening? To save a minute here and there?
Autofill wastes more time than it actually saves
Even without the wasted games not playing what you want to practice for ranked, or just try out, there's also all of the time wasted just trying to get into the game in the first place. Not everyone is content to sit there and just take being autofilled, and will dodge to go do something else. Because they don't see wasting a half hour being worth anything. This fucks over everyone else (as you already know) since they all get shoved back into queue and run the risk of being given a role they don't want .
Then you get the people who are pissed off that after getting the role they wanted last game, the dodge left them either with their secondary role, or support. Guess what happens next. They dodge. And the cycle starts again. The most amount of champion selects I've ever been through in one sitting is 9. 9 fucking champion selects. By the time I actually got into the game finally, an entire game's worth of time had gone by!
Ranked integrity is affected by autofill
The problem is compounded further when you think about how this affects the ranked ladder. How the hell is anyone supposed to know whether or not they actually won that game fighting the enemy team at it's best when autofill is so rampant? You're having entire games lost because this one guy who's a really good top laner and an alright jungler got neither of these roles and was autofilled to something else, where he has little to no experience and is now suddenly a detriment to his team when he starts feeding kills to the rank 7 whatever that actually got their preferred role.
What this boils down to is that ranked is now a cesspool of RNG. You either got a team where everyone got a role they play or are happy with, or you got 1 or more players autofilled to roles they don't play playing against players who got what they want. How are we as players supposed to take the climb seriously when we go on big winstreaks because of lucky matchmaking or horrible loss streaks because we got autofilled or our team got an autofill. I would rather wait 2-3 more minutes for a support/mid/jungle/adc/top who actually know what they are doing than get into champion select quickly and be match with players displaced from their best roles, and I know I'm not the only one. I had a game where My top had queued up for Mid, my Mid had queued up for Jungle, my ADC got what they wanted, I had queued for top, but gotten autofilled to support. Why the hell did we all recieve each other's preferred roles when we all wanted what each of the other people on our team got? What sense does that make?!
If you aren't going to remove autofill, or even make it work better, then could you at least reward the people who don't dodge the autofill? Give them some free IP or a free key fragment for winning or something, I dunno. And I'm not talking about people who queue up for support every game, I mean people who were put into a role they didn't queue up for.
tl;dr Autofill tilts people before they even get into game, wastes more time than it saves, and makes it hard to take ranked seriously
I did not write this, i left a link to who wrote this originally, just to good not to share though