League of Legends is a very straight forward game, even though it's very customizable. You can tecnically play any character in any lane, but it rarely ever works since many champs are design for their respective lane. But not ADC's.
For a while now I have been playing ADC's midlane, mostly Caitlyn and Jhin, and I find them to be extremly strong. And this got me wondering, why do people not try new things and for example play a role like ADC's in midlane. Well, it all has to do with design.
League of Legends at it's core is designed to have some roles in some lanes. Tanks and bruisers in toplane, Mages and Assassins in midlane and ADC's and supportive characters in botlane. And this has perks. You want many people bot to help junglers with Drake. You also want someone more tanky in Toplane to help with Rift Herald. But has this always been the case?
Back in older seasons, this was not the case at all. Jungle was barely a role, Mages was played toplane and botlane was a big hassle since any fun comp worked. But with time new strats came forward from pro-teams that changed the whole meta and in general the whole way to play League. Assassins and Mages went mid, since their Roams were deadly, tanky characters went top for their splitpush capability ect.
But the question still stands, why does not ADC's get played mid. Well, it's because of the meta. Playing an ADC in midlane is risky, since ganks are very effective on you. And that's the reason ADC's get played bot. Pared with a support, they can be legendary since much of the risk goes away. But even though there is a risk, playing ADC in midlane is extremly fun and rewarding, and some would even argue overpowered.
So to summerize, it's risky to play ADC's midlane, but pared with the right team and in a good matchup your pick can change the outcome of the game by miles.