Autofill is just a symptom of a larger problem...

...that not enough people want to play support. The problem is that simple, even if the solution is easier said than done: Riot needs to turn support into a role that more people want to play. I have seen a lot of videos and commentary on autofill and why it sucks, but very little on the underlying problem, which is that playing support sucks.

Yes, I know there are support mains who love to support, but the majority of people avoid the role, or autofill wouldn't be necessary. Personally, I hate playing support for a few reasons:

1. Most supports do so little damage they struggle even to clear minions in a pushing lane. Nothing makes you feel more impotent than trying to beat down a single superminion who is kicking your ass.
2. You can rarely fight anybody 1v1 but the enemy support, unless you are ultra-fed and they are underfed. Forget about 1v2. Sure, you might be able to CC them for days, but really your only real option is to run or get help from your teammates. That is very frustrating.
3. The success of your lane phase is largely reliant on another person. Sure, Junglers have a similar problem with laners who lose/feed their lane or don't follow up properly on ganks, but they can at least choose to ignore their lost cause lanes and farm up. That's not an option as a support. As a support, you are expected to spend the lane phase babysitting the ADC, and the rest of the game peeling for the carries. In fact, the recent controversy with the Support Singed guy only proves that Rito says that a support's place is bot lane, spoon-feeding their ADC. At my ELO, many ADCs are suicidal asshats who run blissfully to their death and then blame you for not keeping them alive. That's no fun.

Yes, there is talk about giving the game more metrics to reward supports... graphs for damage reduced/healed, etc. That will give support mains more information to feel good about after the Victory screen, but it won't give the rest of us much reason to play the role.

What's the solution? I say, give support champions more power, and more damage if they want it. Let them be good enough to be useful to their team even when they're not shadowing another teammate. Sure, their abilities can revolve more around healing/shielding/cc and a little less around damage, but give them the gold income to have the freedom to buy good items. For that matter, make the support items stronger and more expensive. If laners start taking them, do what Riot has done with smite items and make them support-exclusive. In other words, give support players perks that give them an ADVANTAGE over their other teammates, not a burden they need to carry just to be useful.

Make supports the equal of any laner (just with a bit more bent toward CC or healing/shields) with an equal chance to carry games in an obvious way, and I guarantee that people will want to take the role.

All of this is easy to say and very difficult to implement, obviously. Here are some crazy half-baked ideas that would almost certainly be game-breaking without massive adjustments to the game. I want to see stuff like the following:

1. The person with the "support" mantle can create a link with another player (with a cooldown), much like what some of the other support items. While the link is active and you are both in proximity to each other, when either partner last-hits a minion, both people get the gold. If you get a kill on an enemy champion, you split the kill/assist gold between each other evenly. Even if the support is getting all the work done in lane, their ADC will be along for the ride and will eventually do their thing of scaling up and becoming the mid/late game terror. This would inject a lot more money into the game, so adjustments would have to be made, but it would also mitigate games where the support accidentally gets all the kills in laning phase and struggles to turn it into a lead, while their adc throws a hissy fit because they weren't the ones to secure the kills.

2. Make Sightstone free/mandatory (starts in inventory, cannot be sold), or better yet, replace it with an inherent ability so it doesn't use up an item slot. I've always thought it would be nice for junglers to get smite automatically as a third summoner spell that only they can take, while supports get a similar vision ability to what sightstone provides. Having this ability is what opens up their respective role-specific items.

Anyway, that's my 2 dollars.

TL,DR: Make playing support more fun so more people play it. That means allowing supports to be more powerful and autonomous, and maybe get some special perks just for being support. No more long queue times and no more autofill.