While I agree that sending death threats to the designers because ADCs are weak is stupid, there's also the fact that crit builds don't come online until you have 3 items at least, 4 if they have a tank, and you are 100% useless until that point. I just pulled up your match history on here and saw a Lucian game right at the top where you had a mana potion. Your match history on League's own website shows your most recent game as Jarvan 4 on January first, 2016. So if you haven't played in literally a year, don't talk about what is or isn't good right now. Up until very recently, I mained Twitch ADC, the highest win rate ADC this patch, and even when I won, I felt like I really wasn't contributing anything until I had Runaan's, IE, and Statikk Shiv. And even then I still felt like the only thing I could actually do anything to was the enemy squishies until I got LDR. Combine that with the fact that the mid laner and jungler are both coming mid and diving bot lane's turret at level 4 literally every game and you can probably understand why ADC feels so weak, so useless. We need 2,600 + 3,600 + 2,600 gold in items to contribute anything (that's 8,800 gold) to a game, add in another 2,700 for a total of 11,500 gold if you want to kill tanks, and another 3,700 for a Bloodthirster if you want to survive long enough to do all of that. Total gold requirement to be useful as ADC in season 7 is now 15,200. Have fun trying to reach that if you don't get fed or your other lanes are feeding. That's now counting another 1,100 for boots (total now 16,300 for full build). Sure, you CAN 100% carry every single game if you get that far. The problem is getting that far.
Oh, and if you want that Match History thing so you can tell me I'm wrong, here's the link: http://matchhistory.na.leagueoflegends.com/en/#match-history/NA1/208257366 I right clicked on your name, hit open link in new tab, and clicked the Show Match History button and this is what it gave me.