The life expectancy of your average resident of Westeros is nothing to brag about. It turns out near constant wars, White Walkers, and shadow babies are not conducive to living long, happy lives. Given how many characters Game of Thrones has killed off over the years, I do not relish the thought of losing more, but there are certain living major characters whose deaths would have been game changers. For instance, if Cersei had died, Game of Thrones would be on an entirely different course as it headed into Season 7.
Given where Season 6 left off with Cersei stripped of her children, but in possession of the crown and power she had craved since she was a little girl, it would be easy to think the Seven Kingdoms would be better off without Cersei in them. I have to admit some things would be better — Margaery would likely still be alive — but Cersei's death would have destabilized Westeros' power system in some crucial ways. There are several points where Cersei came close to meeting the god of death, but I want to focus on the siege of Blackwater Bay in Season 2. Cersei came very close to poisoning herself and Tommen before Tywin and his army showed up just in time to stop her.
If Tywin and his army had not appeared when they did, the course of the entire series would have been altered.
Cersei has been a key player in the politics surrounding the Iron Throne. Had she and Tommen died before realizing the Battle of Blackwater had turned in favor of the Lannisters, there would have been no Lannister/Baratheon child to take Joffrey's place in the line of succession. As such, the Tyrells plan to murder Joffrey would have effectively ended Joffrey's reign and left no one but Stannis or Myrcella to transfer power to, which in turn means the Tyrells may have reevaluated their plan to dispose of Joffrey before Margaery became pregnant with an heir.
If Cersei was out of the picture, only Tywin would have been left to control his grandson, and Joffrey never showed his grandfather any respect. There is also the matter of Jaime to consider — the loss of Cersei would have left him utterly broken, and committed to protecting their remaining children at any cost. In a reality where Joffrey spent a much longer stint on the Throne, as Lord Commander of the Kingsguard, Jaime would have been forced to do Joffrey's bidding, and left unchecked, Joffrey's demands for power could only have become more out of control.
In the midst of so much turmoil in King's Landing, the High Sparrow's message of peace would have been more appealing than ever, and with a character as deranged as Joffrey in his way, the High Sparrow likely would have taken drastic measures to dethrone Joffrey himself. The remaining Lannisters and Tyrells would have still faced off with the Faith, but would any of them have had the foresight to put into action a plan as deadly as the one Cersei concocted?
Without Cersei in the picture there is an excellent chance Tyrion would never have been accused of murder, Sansa would not have been forced into marriage with Ramsay, and both Oberyn and Myrcella may have lived longer lives. The world of Westeros would not have suddenly become a rosy place without Cersein in it though. Since Cersei would have taken Tommen with her, Joffrey's reign would have lasted longer putting the remaining Lannisters and the Tyrells in a troubling position. The High Sparrow still would have gained power among the small folk and exercised his control over the crown, only this time a living Tywin very likely would have brokered a deal with the man.
Cersei is a character who has long been working behind the scenes in order to rise to the top, and without her machinations many characters' lives would have been improved, but a longer reign from Joffrey and a devastated Jaime are a lethal combination. Cersei may be Game of Thrones' resident evil queen, but she keeps dangerous characters in check and the power vacuum that would exist without her would be deadly.
Images: HBO; Giphy (2)