Why do people think Twitch is the sole reason SKT won that? Do you not realize how important the wombo combo was?
Yes, they had a scaling comp, but they had no kills, no turrets, and no dragons. EDG was well on their way to closing out the game, and had EDG survived, or even turned it around, SKT would have surely lost.
They had 1 single opportunity to get back into the game: take EDG by surprise, keep their team CC'd long enough so the damage can come through, and have enough health left over to get Baron.
They did exactly that. Afterwards, they had enough gold to let their scaling kick in, and EDG couldn't compete.
EDG played damn near perfectly, and if SKT never found that EXTREMELY small window, that game was theirs.