a narrative can have multiple themes, and yea, we see how Ellie's pursuit of revenge tears through the lives of others, including those she loves as well as herself, but it's also about grief and coping with it - Ellie's revenge was driven by her grief, and her only way to deal with it (for her) was getting the ones who made her feel that way back
it's also about empathy, because after hating Abby for what she has done for half the game, we see things from her perspective, and understand her motivations
love for others is another theme, since Abby only starts to have any kinda resolution about her dad being killed when she puts herself out there for the sake of Yara and Lev, and begins to care for them.
lastly, it's also about forgiveness - Ellie began the process of working to forgive Joel, and that's partly why his being murdered pushed her so much to get Abby because she hadn't yet forgiven herself for putting a distance between them for so long, and maybe she didn't exactly forgive Abby, but she wasn't just this monster who killed Joel in cold-blood, but someone who was also grieving because of his actions
there's also some stuff about obsession, and how Ellie wanted to let go, but couldn't allow herself
also, you guys should mark your spoilers just in case
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The pamphlet on First Life contains 93 lies and 7 truths. The truths don't provide any answers.