Golden State is about to sweep the Cavs, but I don't feel sorry for Lebron. A few years ago, he also conspired with a few other stars to all be on Miami making it a superteam and winning a LOT. So really, Lebron is no better.
As for the Warriors being the GOAT, as usual, it is highly debateable. The Lakers of the early 70's won 33 games straight, the old Celtics had 7 HOF players on one team, and don't forget the Jordan Pippen Bulls. The game was also played differently, no guard would move up to do a layup like now without being fouled hard.
I won't go into a GOAT debate for other sports, but I stand by my definition that the GOAT would have to be able to transcend in any era that a game was played, which is a tall order.