I have come to an astounding conclusion, M&G!
After many months of research (which cost the US government about 3 billion in funding), and a lot of suffering on my part, I have finally made a breakthrough!
This astonishing information...is that your ADC is actually a minion.
I know, this is very hard to believe. "They do so much damage!" "They have abilities!" I hear you say.
Yes, yes. This is all true. But plenty of other minions have special abilities. Krugs split when they die, and...shuffles notes Uhm...Ah, yes. Gromp attacks quickly, then slowly. And Baron has a lot of abilities, and does a lot of damage.
I came to this conclusion by carefully studying their behavior. They move somewhat erratically, always try to shove the wave, ignore your pings, don't pay attention to chat (even though it seems they do, it's actually an automated response!), chase enemies blindly - no matter the danger, end up worth 50 or less gold apiece, constantly die under the enemy turret, never leave their lane unless dragged out of it or blindly chasing, always seem to...
And, perhaps most importantly of all, they have the same intelligence level. Minions are, for lack of a better word, completely retarded. As is your ADC. They also seem to act unpredictably, but have an underlying pattern.
I did find a few exceptions to this rule, who, while they behaved. However, upon closer inspection, it was revealed that all of the exceptions on your team were Yasuo, Riven, and support mains that were autofilled, while the ones that were on the enemy team mained marksmen in other lanes, and were autofilled.
After a few more months, I hope to have other information for you, as to why these minions have invaded the roles!