GOAT will always come down to the criteria you personally choose to base your opinion on.
That's good news for Tiger fans. A few years ago he was going to be the GOAT, because he was going to sail past Jack's major record. Now it is something else.
If it is peak golfer or impact on the game, one would have to assume it is somebody like Bobby Jones. He completed the Grand Slam. He even helped design and start the Master's Tournament.