- Darius has a 70% win rate and is banned constantly for a reason.
- Vi can wreck every tank in the game.
- Yasuo doesn't give a crap about armor when each yas can ult off a single yas's ult, and suddenly you have 5 yasuos with a crapton of arpen for the 7 short seconds a teamfight lasts. On top of that, every shiv proc crits, and there's 5 of them. That's like 1200 magic damage to 3 or 4 targets in a teamfight.
- Lee sin can find plenty of room for a last whisper and cleaver, and then out-tank you with his innate lifesteal, shield, and mobility.
- Sion can out-tank pretty much EVERYONE and also still find room for cleaver/lw (I'm basically describing every ad fighter, moving on)
- Gnar can just stack percent max health magic damage. Imagine 5 gnars focusing one target, proccing his w twice every second, and you get the picture.
- Vayne can do the same thing, only it's true damage. Basically, if 5 vayne's focus the same target, that target disappears in about 1.5 seconds.
- Fiora builds a crapton of ad and from it, a single fiora can do about 70% of a target's max health in true damage in about 2 seconds from an ult and one passive proc. Now if 4 other Fiora's are helping her, and then after that target, they move onto the next one with ANOTHER ult, and then another ult on the next, and just plop janna heals all over the place... again, you get the picture.
- Why the heck of all AD you claim GP is an exception? He generally doesn't do so well early. His barrels are stupidly predictable. He's easily out-traded til late game by most standard OfA picks. Before late game arrives, he's probably lost or surrendered.
Basically, the only ad champs you're ACTUALLY describing are ranged adc's with no innate shred. They suffer from poor early games, compounded by split cs usually in two lanes, 'cause who bothers jungling an adc? Not to mention jungle items usually suck on ranged adc's. You're basically looking at a midgame where, yes, the other team can have enough armor while everyone on your team is still working on their second item. It's not that adc's can't win out against tanks. Put a couple of them on bork/runaan's/cleaver duty, have everyone get lw's and bt's, and you're golden. But that takes too long to build up as it is.
Oh, but honestly, the real problem with adc's is that in an all adc team, there's no one to peel for them. So they just get blown up. By mages, by fighters. Heck, by tanks. Armor has little to do with it if you think about it.
Bottom line: You're wrong.