“Men’s lives have meaning, not their deaths.” After all, I could just as easily ask what the point of Ned was, given that he didn’t make it past book one. I don’t get the idea that if you don’t make it to endgame, you “didn’t add anything to the story,” or indeed that making it to endgame automatically means you did add to the story. For me, that’s not the measuring stick at all. This is why Jon Connington matters:
I rose too high, loved too hard, dared too much. I tried to grasp a star, overreached, and fell.
This is why Doran and Arianne Martell matter:
The words still burned as bright as fire in her memory. “‘One day you will sit where I sit and rule all Dorne,’ you wrote him. Tell me, Father, when did you decide to disinherit me? Was it the day that Quentyn was born, or the day that I was born? What did I ever do to make you hate me so?” To her fury, there were tears in her eyes.
“I never hated you.” Prince Doran’s voice was parchment-thin, and full of grief. “Arianne, you do not understand.”
And this is why Aegon matters. What they add are layers to and angles on many of the Song’s central motifs: doomed hope, tragic ignorance, the bittersweet fall into knowledge, etc. They offer their perspectives, their hopes and fears, their stories. Now of course, GRRM has to ground those stories in the larger plot, which he has–Team Aegon is the culmination of the What Is Varys Up To mystery we’ve been exploring since the first book, they allow the Martell tragedy-cluster to reach its climax, and as GRRM himself told us in Dany V ACOK, mummer’s dragons are there to give the heroes (in this case, Dany) something to fight. In other words, the relevant characters are not only (IMO) compelling in and of themselves, but they’re being set up to enrich and progress the other story elements around them. They’re not random nor overkill.
For me, though, the movements of the plot are a framework you use to support and draw out what we really care about, which is what the story means, both intellectually and emotionally. It’s not that Luke blew up the Death Star. It’s that Luke, the character we know, blew up the Death Star, and that was the perfect thing for his story in ways both obvious and not that are enjoyable to dwell upon and talk about. Plot is structure, scaffolding, a means to an end, a vehicle (expertly constructed, one always hopes) for delivering thoughts and feels. No one loves a painting for its subject matter alone, and I don’t think you determine a character’s worth purely by what the wiki will tell you they contributed to the story. IMO the ultimate example of that in ASOIAF is Quentyn.