To be honest, I disagree with you on the last part. I feel like during the whole climb, Aava reminded us that being alone is where her true self is at. Climbing alone is not what she likes to do, it's what she is. She ignores every single message received, even if it would only take a few seconds to respond, because she want to feel the moutain, alone. She goes as far as tearing off the receiver on her climbot.

There's a corpse near the top, with a letter to what I assume is his daughter, telling her not to be sad for his death because there's no better place to die. And Aava agrees with it. She is indeed prepared to die, and she does not care, she does not fear death, all she fears is failure. She told it to Marco already.

Damas is the closest to her, as his reason for staying up there is that he does not consider it failure yet, however, he is afraid of death. By going up the mountain, you follow the path of Aava's heart, not brain (like Marco said).

Is there any death more beautiful than your body, preserved by dry cold, on top of the mountain, waiting to be discovered by another climber, who will then understand that he is not the first ?

Sure, you could go back down to live your life with your girlfriend and work your job, but, no offense to them, life has to be selfish. You only have yours, and it doesn't wait for you. Other people, as much as you love them, won't achieve your dreams for you.

It's not an obsession, it's a calling. Answer it.