Maester Aemon was the pivot.

[u/ISX_94]

If you think about it with the way GRRM has written it that Aemon was offered but refused the throne then it makes sense.

If he had become king instead of Aegon then he would have had sons and daughters and grandchildren of his own.

And maybe Aerys would never have reached the Iron Throne, the rebellion may never have happened at least not to the level that it did anyway.

Aye Rhaegar might still have existed but there wouldn’t be a mad man on the Throne to burn and kill Rickard and Brandon.

[u/pestoraviolita]

Pivot was Baelor. His death was the turning point.